Post on 16-Mar-2020
3P Prinz Pump Manufacturing Company
TWIN SCREW PUMPS
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Lucca, 15 June 2016
3P Prinz Pump Manufacturing Company
TABLE OF CONTENT
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3P Prinz Pump Manufacturing Company
1) INTRODUCTION TO THEORY OF TWIN SCREW PUMPS
2) FEATURES AND ADVANTAGES
3) BASIC EXECUTIONS
4) APPLICATION FIELDS
5) 3P PRINZ TWIN SCREW PUMP RANGE
6) 3P PRINZ MODEL DE-CODIFICATION
7) MATERIALS SELECTION
8) SIZING OF TWIN SCREW PUMPS
9) FLUIDS HANDLED
10) NPSHr AND SUCTION LIFT
11) PUMP EXECUTIONS FOR THE MAIN SECTORS
12) CRITICAL APPLICATIONS
13) PERFORMANCE TEST STANDARDS
14) API 676 COMPLIANCE AND DEVIATIONS
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3P Prinz Pump Manufacturing Company
The PERA-PRINZ® Screw Pumps are Rotating Positive Displacement Pumps, externally or
internally supported.
One or Two Pairs of Screws, which operate without being in contact with each other,
ensure a constant flow, pulsation-free, together with a high suction lift capability with
very low NPSH values.
Horizontal Installation is supplied as standard while Vertical Installation is supplied on
request.
External supports and gears is supplied as Standard while Internal supports and gears
can be supplied on request, in case the pumped fluid is sufficiently clean and lubricating.
PERA-PRINZ® TWIN SCREW PUMPS
SINGLE AND DOUBLE END POSITIVE DISPLACEMENT PUMPS
Series HM – HR – HD – UD – JD – SR – SD
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3P Prinz Pump Manufacturing Company
The Screws Pair rotates inside the Pump Enclosure, creating several separate chambers and pushing the fluid
trapped inside in accordance with the progression of the screws pitch.
The flow rate is particularly uniform and pulsation-free, and the pumped fluid flows in an axial direction (not
circumferentially, as it happens in the centrifugal pumps).
Fluids that are sensitive to shear forces or turbulent flows are subject only to very limited stresses during the
pumping phase:
Thanks to the absence of pulsations, to the low flow internal velocities, to the minimization of the centrifugal
movements and to the absence of contact between the screw rotors, the pumped product does not suffer of
changes of volume, texture, aspect and properties.
Thanks to the low inertia of the rotating parts, the Screw Pumps can
work at rotating speeds higher than other Positive Displacement Pumps
of equivalent volume chambers.
PERA-PRINZ® TWIN SCREW PUMPS WORKING PRINCIPLE
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3P Prinz Pump Manufacturing Company
Timing Gears
PERA-PRINZ® TWIN SCREW PUMPS WORKING PRINCIPLE
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2 Opposite Screws mounted on 1 Shaft
Bearings
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BY APPLICABLE STANDARD:
• Manufacturer Standard
• API 676
PERA-PRINZ® TWIN SCREW PUMPS EXECUTIONS
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• The Radial and Axial Loads are balanced on the Double Volute Twin Screw Pumps.
• Only the Radial Loads are balanced on the Single Volute Twin Screw Pumps.
BY MOUNTING:
• Overhung Twin Screws
/ Single Volute (Single End)
/ Single Pair of Screws
• Between Bearing Twin Screws
/ Double Volute (Double End)
/ Double Pair of Screws
3P Prinz Pump Manufacturing Company
BY INSTALLATION:
• Horizontal Shaft (Side – Top Flanges)
• Vertical Shaft (Side – Side Flanges)
• Horizontal Shaft (Side – Side Flanges)
PERA-PRINZ® TWIN SCREW PUMPS EXECUTIONS
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BY LINER:
• Non-Replaceable Liner
- Cast Body
• Replaceable Liner
– Welded Fabricated Steel Body
PERA-PRINZ® TWIN SCREW PUMPS EXECUTIONS
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3P Prinz Pump Manufacturing Company
• Self Priming
• They ensure a constant flow, pulsation-free
• High Suction Lift Capability – the pump NPSH being very low
• Suitable to pump fluids with low, medium, high and very high viscosity.
Very well suited to pump very viscous liquids, sensitive to shear forces and turbulences thanks to the low Internal
velocities given by the screws movement.
• Low Noise Level and Low Vibrations
• The Screws are Contactless and Wear out is minimized
PERA-PRINZ® TWIN SCREW PUMPS ADVANTAGES
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3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS ADVANTAGES ON TANK STORAGE
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CENTRIFUGAL PUMPS FOR TANK STORAGE:
- Capable of pumping fluids only up to approximately 150 cSt
- Generate pressure in accordance to their characteristic Curve
- Not well suitable to variable speed operation
TANK STORAGE
PRODUCTS OFFLOADING
BB1 Centrifugal Pump:
1500 m3/h @ 100 mwc
Max 150 cSt
CRUDE OIL CARRIER
BB1 Centrifugal Pump:
800 m3/h @ 100 mwc
Max 150 cSt
OIL TANK BARGE
OH1 Centrifugal Pump:
150 m3/h @ 100 mwc
Max 150 cSt
OIL TRUCK - RAILCAR
PUMP 1
PUMP 3
PUMP 2
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS ADVANTAGES ON TANK STORAGE
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TWIN SCREW PUMPS FOR TANK STORAGE:
• Capable of Operating at High Angular Speeds thanks to the screws low inertia, allowing a high range of flow rates if
the pumps are driven by a Variable Speed Drive or by an Inverter
• Constant Flow regardless pressure changes (in particular when viscous fluids are pumped)
• Capability of handling a Wide Range of viscosities and pressures
TANK STORAGE
PRODUCTS OFFLOADING
1500 m3/h @ 100 mwc
Max 500 cSt
CRUDE OIL CARRIER
800 m3/h @ 100 mwc
Max 1000 cSt
OIL TANK BARGE
150 m3/h @ 100 mwc
Max 2000 cSt
OIL TRUCK - RAILCARONE PUMP FOR ALL SERVICES
ONLY ONE INSTALLATION:
Less installation costs
Less pipe work
3P Prinz Pump Manufacturing Company
• Flow can be reversed (reversibility) in low pressure applications, upon request
• Entrapped Air or Gas in the Liquid are tolerated up to 50-60% volume (multi-phase service on request)
• Capability of Dry Running for a limited period and in particular conditions
• Compact Design and Dimensions
PERA-PRINZ® TWIN SCREW PUMPS ADVANTAGES
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3P Prinz Pump Manufacturing Company
• CAPACITY: from 1 m3/h up to 3.500 m3/h [from 4.5 GPM up to 15,500 GPM]
• CASING PRESSURE: up to ANSI 900 - 149 barg [2160 Psig]
• DIFFERENTIAL PRESSURE: up to 60 bar [870 Psi]
• NPSHr: down to 1,5 meters [5 ft]
• VISCOSITIES: from 0,5 cSt up to 50.000 cSt (up to 250.000 cSt in special execution)
• PUMP NOISE LEVEL: up to 85 dB for small and medium sizes
• GAS/AIR HANDLING: Gas/Air Content up to 50% (dissolved, not slug)
• TEMPERATURE: up to 300°C [573°F]
PERA-PRINZ® TWIN SCREW PUMPS
GENERAL FEATURES AND PERFORMANCES
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3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN APPLICATIONS
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FLUIDS HANDLED:
- CRUDE OIL (RAW OR REFINED)
- CRUDE OIL MIXED WITH WATER
- CRUDE OIL MIXED WITH WATER AND GAS
- ALL TYPE OF HYDROCARBONS, LIGHT AND HIGH VISCOSITY (FROM GASOLINE TO BITUMEN)
- OIL / WATER EMULSIONS, INCLUDING SLOPS, PRODUCED WATER
- CHEMICALS (METHANOL, INHIBITORS)
OIL FIELDS
OFFSHORE PLATFORMS
FPSOs & FSOs
OIL & GAS
UPSTREAM
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN APPLICATIONS
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FLUIDS HANDLED:
- CRUDE OIL (RAW OR REFINED)
- CRUDE OIL MIXED WITH WATER
- CRUDE OIL MIXED WITH WATER AND GAS
- ALL TYPE OF HYDROCARBONS, LIGHT AND HIGH VISCOSITY (FROM GASOLINE TO BITUMEN)
- OIL / WATER EMULSIONS, INCLUDING SLOPS, PRODUCED WATER
- CHEMICALS (METHANOL, INHIBITORS)
OIL PIPELINE
OIL TANKER / BARGE
REFINERY
PETROCHEMICAL PLANTS
TANK STORAGE TERMINALS
OIL & GAS
MIDSTREAM
DOWNSTREAM
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN APPLICATIONS
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FLUIDS HANDLED:
- CRUDE OIL
- ALL TYPE OF HYDROCARBONS, LIGHT AND HIGH VISCOSITY:
- GASOLINE
- DIESEL / NAPHTA
- LUBE OIL
- HEAVY FUEL OIL / MAZOUT
- BITUMEN / ASPHALT / TAR
- OIL / WATER EMULSIONS, INCLUDING SLOPS
- TANK STRIPPING FOR ALL FLUIDS
OIL TANKERS
BARGES
CARRIERS
CRUISE SHIPS
NAVY SHIPS
SUPPORT VESSELS
MARINE &
SHIPBUILDING
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN APPLICATIONS
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OTHER APPLICATION FIELDS
Power Plants Light and Heavy Liquid Fuels Fuel Burner Oils Lube Oil
Food & Beverage and Pharmaceutical
Dairy Products (Yogurt, Cream) Fruit Juices, Pastes, Jam Syrups and Molasses
Vegetable and Animal Oils / Fats Pastes Processed Meat
Alcohol / Liquors Chocolate Caramel and Fudge
Sauces / Concentrates Dough Beer and Wines
Chemical Industry
Acids and Concentrated Acids Solvents Lubricating Oils
Aliphatic Acids Additives Wax
Glycerin Latex Lye
Glues Alkaline Solutions Emulsions
Soaps Caustic Soda Solvents
Liquid Sulfur Rubber Suspensions Paraffin
Polymers / Fibers Suspensions Polyester Resins
General IndustryColouring & Pigmented Pastes Thickeners Additives
Enamels and Paints Emulsions Hydraulics
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS SERIES
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TWIN SCREW PUMP CAPACITY RANGE DESIGN PRESSURE MARKET
HM Series
Single Pair of Screws,
External Timing Gears up to 80 m3/h 20 Bar Oil&Gas, Industrial, Marine
HR Series
Double Pair of Screws, Light & Compact Design,
External Timing Gears up to 3500 m3/h 14 Bar Oil&Gas, Industrial, Marine
HD Series
Double Pair of Screws, Heavy Duty Design,
External Timing Gears up to 3500 m3/h 25 Bar Oil&Gas, Industrial, Marine
UD Series
Double Pair of Screws, High Pressure Design,
External Timing Gears up to 1000 m3/h 50 Bar Oil&Gas, Industrial, Marine
JD Series
Double Pair of Screws, Very High Pressure Design,
External Timing Gears up to 600 m3/h 100 Bar Oil&Gas, Industrial
SD Series
Double Pair of Screws, Heavy Duty Design,
Internal Timing Gears up to 1200 m3/h 25 Bar Oil&Gas, Industrial, Marine
SR Series
Double Pair of Screws, Light & Compact Design,
Internal Timing Gears up to 1200 m3/h 14 Bar Oil&Gas, Industrial, Marine
VDC Series
Double Pair of Screws, Heavy Duty Design,
Vertical Submerged,
Internal Timing Gears up to 1000 m3/h 50 Bar Oil&Gas, Marine
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS COVERAGE CHART
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0
500
1000
1500
2000
2500
3000
3500
0 10 20 30 40 50 60 70
Ca
pa
cit
y(m
3/h
)
Differential pressure(bar)
Twin screw pump coverage chart
3P Prinz Pump Manufacturing Company21
Pump type TWIN SCREW PUMPS – EXTERNAL TIMING GEARS
Pump Series HR Series: HRV Series
Installation Options: Horizontal Vertical
Executions:Standard & API 676 with deviations - Timing Gears - External Gears and
Bearings
Optimized for Applications in: Petrochemical, Chemical, Shipbuilding, General Industry, Oil&Gas
Suitable to Fluid having the following properties:
Abrasive and not Abrasive
Corrosive (Alkaline / Acid / Aggressive) and not Corrosive
Low / Medium / High / Very High Viscosities
Not Lubricating or Lubricating
Medium / High percentage of Gas or Air dissolved in Liquid
Slightly Dirty (small soft particles)
Pump Series HR Series:
Maximum design pressure: 14 bar (standard) [204 psig]Flow rates: up to 3500 m3/h [15400 GPM]Viscosity of the pumped fluid: up to 35.000 cSt
Pipe Nominal Size DN: from 50 to 750 [from 2’’ up to 30’’]Rotation speed: from 200 up to 2200 rpm
Temperature range: -46 / +300 °C [-51 / +572 °F]Pulsations: Minimized (almost zero)
Bearing types: External Bearings and Gears in oil bath / grease
3P Prinz Pump Manufacturing Company22
Pump type TWIN SCREW PUMPS - EXTERNAL TIMING GEARS
Pump Series HD Series: HDL Series: HDV Series
Installation Options:Horizontal (Cast Casing)
Horizontal (Fabricated Steel Casing, with ReplaceableLiner) Vertical
Executions: Standard & API 676 - Timing Gears - External Gears and Bearings
Optimized for Applications in: Oil&Gas, Petrochemical, Chemical, Shipbuilding, General Industry
Suitable to Fluid having the following properties:
Abrasive and not Abrasive
Corrosive (Alkaline / Acid / Aggressive) and not Corrosive
Low / Medium / High / Very High Viscosities
Not Lubricating or Lubricating
Medium / High percentage of Gas or Air dissolved in Liquid (Multiphase versions available)
Slightly Dirty (small particles)
Pump Series HD Series:
Maximum design pressure: 20 bar (standard) [300 psig]Flow rates: up to 3500 m3/h [15400 psig]Viscosity of the pumped fluid: up to 35.000 cSt
Pipe Nominal Size DN: from 50 to 750 [from 2’’ up to 30’’]Rotation speed: from 200 up to 2200 rpm
Temperature range: -46 / +350 °C [-51 / +662 °F]Pulsations: Minimized (almost zero)
Bearing types: External Bearings and Gears in oil bath
3P Prinz Pump Manufacturing Company
Pera Prinz® - Comparison between HR and HD Series
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3P Prinz Pump Manufacturing Company
Pera Prinz® - Some HD Series pumps dimensions
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3P Prinz Pump Manufacturing Company25
Pump type TWIN SCREW PUMPS - EXTERNAL TIMING GEARS
Pump Series UD Series:UDL Series &JDL Series
UDV Series &JDV Series:
Installation Options:Horizontal (Cast Casing)
Horizontal (Fabricated Steel Casing, with ReplaceableLiner) Vertical
Executions: Standard & API 676 - Timing Gears - External Gears and Bearings
Optimized for Applications in: Oil&Gas, Petrochemical, Chemical, Shipbuilding
Suitable to Fluid having the following properties:
Abrasive and not Abrasive
Corrosive (Alkaline / Acid / Aggressive) and not Corrosive
Low / Medium / High / Very High Viscosities
Not Lubricating or Lubricating
Medium / High percentage of Gas or Air dissolved in Liquid (Multiphase versions available)
Slightly Dirty (small particles)
Pump Series UD Series: JD Series_
Maximum design pressure: 50 barg [730 psig]149 barg [2170 psig]max ANSI 900 rating
Flow rates: up to 1000 m3/h [4000 GPM] up to 600 m3/h [2650 GPM]Viscosity of the pumped fluid: up to 35.000 cSt up to 35.000 cSt
Pipe Nominal Size DN: from 50 to 400 – from 2’’ to 16’’ from 50 to 400 – from 2’’ to 14’’
Rotation speed: from 200 up to 2200 rpm from 200 up to 2200 rpm
Temperature range: -46 / +350 °C [-51 / +662 °F] -46 / +350 °C [-51 / +662 °F]Pulsations: Minimized (almost zero) Minimized (almost zero)
Bearing types: External Bearings and Gears in oil bath External Bearings and Gears in oil bath
3P Prinz Pump Manufacturing Company26
SD Series: High Capacity Double End Twin Screw Pump
– Internal Gears and Bearings (Wetted and cooled by the Pumped Fluid);
Maximum Pressure 16 barg [232 psig] ;
Higher Pressures Executions available on request;
Suitable only to Clean and Lubricating Fluids (no Abrasive Particles)
SD-V Series: Vertical Installation Version of SD Series
SR Series: High Capacity Double End Twin Screw Pump
– Internal Gears and Bearings (Wetted and cooled by the Pumped Fluid);
Maximum Pressure 14 barg [204 psig] ;
Suitable only to Clean and Lubricating Fluids (no Abrasive Particles)
SR-V Series: Vertical Installation Version of SR Series
Pump type TWIN SCREW PUMPS - INTERNAL TIMING GEARS
3P Prinz Pump Manufacturing Company27
Pump type VERTICAL TWIN SCREW PUMPS - INTERNAL TIMING GEARS
Pump Series VDC Series:
Installation Options: Vertical - Submerged
Executions: Standard & API 676 - Timing Gears - External Gears and Bearings
Optimized for Applications in: Oil&Gas, Petrochemical, Shipbuilding
Suitable to Fluid having the following properties:
Abrasive and not Abrasive
Corrosive (Alkaline / Acid / Aggressive) and not Corrosive
Low / Medium / High / Very High Viscosities
Not Lubricating or Lubricating
Medium / High percentage of Gas or Air dissolved in Liquid (Multiphase versions available)
Slightly Dirty (small particles)
Pump Series VDC Series:
Maximum design pressure: 50 barg [730 psig]Flow rates: up to 600 m3/h [2650 GPM]Viscosity of the pumped fluid: up to 35.000 cSt
Pipe Nominal Size DN: from 50 to 400 – from 2’’ to 16’’
Rotation speed: from 200 up to 2200 rpm
Temperature range: -46 / +350 °C [-51 / +662 °F]Pulsations: Minimized (almost zero)
Bearing types: Bearings and Gears wetted by Pumped Fluid
3P Prinz Pump Manufacturing Company28
Pump typeSCREW PUMPS - TIMING EXTERNAL GEARS
OVERHUNG SCREWS – SINGLE VOLUTE
Pump Series HM Series: HM-V Series:
Installation Options: Horizontal Vertical
Executions: Standard & API 676 - Timing Gears - External Gears and Bearings
Optimized for Applications in:
Oil&Gas, Petrochemical, Chemical, Shipbuilding, Power Generation, General Industry
Suitable to Fluid having the following properties:
Abrasive and not Abrasive
Corrosive (Alkaline / Acid / Aggressive) and not Corrosive
Low / Medium / High Viscosities
Not Lubricating or Lubricating
Medium percentage of Gas or Air dissolved in Liquid
Slightly Dirty (small particles)
Pump Series HM Series:
Maximum design pressure: 20 bar (standard)
Flow rates: up to 80 m3/h [353 GPM]Viscosity of the pumped fluid: up to 35.000 cSt
Pipe Nominal Size DN: from 40 to 100 [from 1.1/2’’ to 4’’]Rotation speed: from 200 up to 3600 rpm
Temperature range: -46 / +300 °C [-51 / +572 °F]Pulsations: Minimized (almost zero)
Bearing types: External Bearings and Gears in oil bath
3P Prinz Pump Manufacturing Company29
PERA-PRINZ® TWIN SCREW PUMPS – HM250
3P Prinz Pump Manufacturing Company30
PERA-PRINZ® TWIN SCREW PUMPS – HM200 VERTICAL (OFFSHORE / MARINE)
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS WITH ELECTRIC MOTOR – HD PUMPS WITH DRAIN
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3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS WITH ELECTRIC MOTOR – HD PUMPS WITHOUT DRAIN
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3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS WITH ELECTRIC MOTOR – HM PUMPS
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3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MODEL DE-CODIFICATION:
HD, HR, UD, JD, SD, SR Series
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HD 0 12 G2 C2 0 T01 NZ
PUMP SERIES:HD, HR, UD, JD, SD, SR
PUMP SIZE MODEL:
HD, UD, JD, SD:06, 07, 10, 12, 14, 17, 20, 22, 25, 30
HR, SR:09, 14, 18, 23, 30, 37, 50
MATERIAL OF BODY
MATERIAL OF SCREWS + SHAFTS
LINERMATERIAL
TYPE OF MECHANICAL SEAL:T01: component typeT02: single, cartridge API 682T03: double, cartridge API 682T04: single cartridge, not APIT0B: Packing type sealOthers: please contact 3P Prinz
ACCESSORIES / OPTIONS
PUMP EXECUTION:0 (no liner)L (with liner)V (vertical)
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MODEL DE-CODIFICATION:
HM Series
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HM 050 G2 C2 T01 NZ Z
PUMP SERIES:HM
PUMP SIZE MODEL:
HM: 050, 100, 200, 250, 300
MATERIAL OF BODY
MATERIAL OF SCREWS + SHAFTS
TYPE OF MECHANICAL SEAL:T01: component typeT02: single, cartridge API 682T03: double, cartridge API 682T04: single cartridge, not APIT0B: Packing type sealOthers: please contact 3P Prinz
ACCESSORIES / OPTIONS
PUMP EXECUTION:Z (no liner)V (vertical)
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN MATERIALS USED
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MATERIALS DESCRIPTION MATERIAL INTERNATIONAL CODE
Cast Iron GG25 (G25)
Ductile Cast Iron GJS-400 (GGG400)
Carbon Steel (Casting) ASTM A216 WCB
Carbon Steel (Fabricated) ASTM A105 / ASTM A516 Gr.60
Carbon Steel (Barstock / Forging) ASTM A105
Low Temperature Carbon Steel (Casting) ASTM A352 LCB
Low Temp. Carbon Steel (Barstock/Forging) ASTM A350 LF2
Nickel-Aluminium Bronze ASTM B148 type
Stainless Steel 12% (Cast) CA6NM
Stainless Steel 12% (Barstock/Generic) AISI 420
Stainless Steel 316 grade (Cast) ASTM A351 CF8M (1.4408)
Stainless Steel 316L grade (Cast) ASTM A351 CF3M (1.4404)
Stainless Steel 316/316L grade (Barstock) ASTM A479 or A276 316 or 316L
Stainless Steel 17-4PH grade (Barstock) ASTM A564 630 or commonly 17-4PH (1.4542)
Stainless Steel 431 grade (Barstock) AISI 431 (1.4057)
Duplex stainless steel 22% Cr (Cast) ASTM A890 Grade 4A or A995 Gr.4A (1.4462)
Duplex stainless steel 22% Cr (Barstock) ASTM A479 F51 / UNS S31803 (1.4462)
OTHER MATERIALS: PLEASE CONTACT 3P PRINZ
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN MATERIALS COMBINATIONS
HD, UD, JD, SD Series
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REFINED HYDROCARBON PRODUCTS (not corrosive, low water content):
GASOLINE, DIESEL, NAPHTA, MAZOUT, HEAVY FUEL OIL, LUBE OIL
Casing Material Screws Material Shafts Material Stuffing Box Material
GG25 GJS-400 or AISI 4140 AISI 4140 A105 / A516 Gr.60
GJS-400 GJS-400 or AISI 4140 AISI 4140 A105 / A516 Gr.60
BITUMEN, TAR (WITH HEATING JACKET)
Casing Material Screws Material Shafts Material Stuffing Box Material
Fabricated Carbon Steel
+ GG25 Liner AISI 4140 AISI 4140 A105 / A516 Gr.60
Fabricated Carbon Steel
+ GG25 Liner AISI 431 or AISI 420 17-4PH A105 / A516 Gr.60
SWEET CRUDE OILCasing Material Screws Material Shafts Material Stuffing Box Material
ASTM A216 WCB
(GG25 or GJS-400 when allowed) AISI 4140 AISI 4140 A105 / A516 Gr.60
Fabricated Carbon Steel
+ GG25 Liner AISI 431 or AISI 420 17-4PH A105 / A516 Gr.60
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN MATERIALS COMBINATIONS
HD, UD, JD, SD Series
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SOUR CRUDE OIL
Casing Material Screws Material Shafts Material Stuffing Box Material
ASTM A216 WCB,
NACE MR-0175 AISI 420 or AISI 316 17-4PH A105 / A516 Gr.60
Fabricated Carbon Steel
+ A216 WCB Liner , NACE MR-0175
AISI 431 or
Duplex 22% Cr 17-4PH A105 / A516 Gr.60
AISI 316/316L (Cast or Fabricated) Duplex 22% Cr Duplex 22% Cr AISI 316 / 316L
Duplex 22% Cr (Cast)
Duplex 22% Cr or
Superduplex 25%Cr
Duplex 22% Cr or
Superduplex 25%Cr Duplex 22% Cr
CHEMICALS
Casing Material Screws Material Shafts Material Stuffing Box Material
AISI 316/316L (Cast or Fabricated)
AISI 316/316L
or AISI 431 or 17-4PH 17-4PH AISI 316 / 316L
Bearing Housing and Timing Gear Housing: Cast Iron or Fabricated Steel
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN MATERIALS COMBINATIONS
HD, UD, JD, SD Series
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CHEMICALS
Casing Material Screws Material Shafts Material Stuffing Box Material
AISI 316/316L (Cast or Fabricated)
AISI 316/316L
or AISI 431 or 17-4PH 17-4PH AISI 316 / 316L
HYDROCARBONS WITH SEAWATER CONTENT / SEAWATER (Example: Slops)
Casing Material Screws Material Shafts Material Stuffing Box Material
GG25 or GJS-400 Duplex 22% Cr 17-4PH A105 / A516 Gr.60
Nickel-Alum Bronze Duplex 22% Cr Duplex 22% Cr AISI 316 / 316L
Super Duplex 25% Cr
(Cast) Super Duplex 25%Cr Super Duplex 25%Cr Super Duplex 25% Cr
Bearing Housing and Timing Gear Housing:
Cast Iron or Fabricated Steel
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS MAIN MATERIALS COMBINATIONS
HR, SR Series
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REFINED HYDROCARBON PRODUCTS (not corrosive, low water content):
GASOLINE, DIESEL, NAPHTA, MAZOUT, HEAVY FUEL OIL, LUBE OIL
Casing Material Screws Material Shafts Material
Stuffing Box Material (including Bearing
Housing and Timing Gear Housing)
GG25 GJS-400 or AISI 4140 17-4PH A105 / A516 Gr.60
GJS-400 GJS-400 or AISI 4140 17-4PH A105 / A516 Gr.60
SWEET CRUDE OIL
Casing Material Screws Material Shafts Material
Stuffing Box Material (including Bearing
Housing and Timing Gear Housing)
GG25 AISI 4140 17-4PH A105 / A516 Gr.60
GJS-400 AISI 4140 17-4PH A105 / A516 Gr.60
HYDROCARBONS WITH SEAWATER CONTENT / SEAWATER (Example: Slops)
Casing Material Screws Material Shafts Material
Stuffing Box Material (including Bearing
Housing and Timing Gear Housing)
GG25 Duplex 22% Cr 17-4PH A105 / A516 Gr.60
GJS-400 Duplex 22% Cr 17-4PH A105 / A516 Gr.60
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – INFLUENCE OF VISCOSITY
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LOW VISCOSITY FLUIDS EFFECTS:
- Backflow (Slippage) increases
- Volumetric Efficiency decreases
- Less friction losses / Higher Mechanical Efficiency
- Speed should be increased up to 1450 - 1800 rpm (or even more)
- It is not recommended to run the pump at low speeds with low viscosities (limited differential
pressures and capacity)
LOWER DIFFERENTIAL PRESSURE LIMITATION
LOWER CAPACITY
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – INFLUENCE OF VISCOSITY
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HIGH VISCOSITY FLUIDS EFFECTS:
- Backflow (Slippage) decreases
- Volumetric Efficiency increases
- Higher friction losses / Lower Mechanical Efficiency
- Speed should be decreased to low speed in order to fill up the chambers without formation of
vacuum in the suction
- It is not recommended to run the pump at high speeds with high viscosities (risk of malfunctioning
of the pump because of vacuum in the suction)
HIGHER DIFFERENTIAL PRESSURE POSSIBLE
HIGHER CAPACITY
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – INFLUENCE OF VISCOSITY
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FLUIDS BEHAVIOUR:
- NEWTONIAN FLUIDS: Viscosity is not influenced by the shear force
Viscosity remains constant when the fluid flows through the pump
- NON-NEWTONIAN FLUIDS: Viscosity is influenced by the shear force (time dependent viscosity
Viscosity drops if higher shear is applied when fluid flows through the pump
FLUID TEXTURE MAY CHANGE AFTER SHEAR IS APPLIED
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – INFLUENCE OF VISCOSITY
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SHEAR SENSITIVE FLUIDS:
- SOME NON-NEWTONIAN FLUIDS
- EMULSIONS (water+oil, water+oil+air)
TWIN SCREW PUMPS HANDLE THE FLUID WITH A LOW SHEAR :
- The main part of the fluid is pumped with an axial movement (not centrifugal, not turbulent), without
acceleration and with low shear
- The small part of the fluid that back flows
through the gaps between screws
and liner is pumped with higher shear
HIGH SHEAR / TURBULENCE CAUSES FOAM
3P Prinz Pump Manufacturing Company45
CENTRIFUGAL PUMPS OR OTHER HIGH SHEAR PUMPS (example Gear Pumps)
HIGH SHEAR / TURBULENCE CAUSES FOAM
when oil/water emulsions are pumped;
Light hydrocarbons may become gas
when depressurized
TWIN SCREW PUMPS AVOID THE FORMATION OF FOAM AND INCREASE PRODUCTIVITY
Foam decreases productivity
and may cause downtimes
Production Costs increase
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – GAS HANDLING
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Twin Screw Pumps can handle a reasonable percentage of Gas dissolved in the liquid
Depending on the application, they can handle up to 50% of Gas!
An analysis of the application shall be executed in order to confirm suitability:
- Type of application (Upstream or Downstream)
- Availability of all the Process Parameters
- How the Gas is mixed in the Fluid: Dissolved? Gas Bubbles? Gas Slugs?
MULTIPHASE PUMPS
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – HANDLING SAND PARTICLES
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Twin Screw Pumps can handle a small quantity of sand dissolved in the liquid.
It is important to know the Sand Particle Size Distribution.
The Sand Particles will increase wear on the screws / liner.
The pump performance may lower due to increased clearance
that increases backflow.
It is not possible to predict the wear out caused by sand particles, but some actions can be taken
during offer and design stage:
Examples: - Hardening of Screws and Liner (including Tungsten Carbide Overlay)
- Replaceable Liners
- Increased clearances between screw/screw and screws/liner
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – HANDLING SAND PARTICLES
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WORST CONDITIONS FOR PUMPING SAND PARTICLES:
- Fluid Viscosity is Low
- High Pump RPMs
- Higher Differential Pressures
- Percentages of Solid Particles higher than 0,01% in volume
Pumping low viscosity liquid with sand particles at high speeds increases sensitively the abrasion
effect
PUMP PERFORMANCES MAY DECREASE QUICKLY
Frequent maintenance and spare parts replacement
It is important to select the right pump execution and materials
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SELF PRIMING – DRY RUNNING
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SELF PRIMING
Twin Screw Pumps are Self Priming if the internal chamber is wet
(slightly filled with fluid)
DRY RUNNING
Twin Screw Pumps, thanks to the non-contacting screws, can run dry
Standard mechanical seals will heat up quickly during dry running:
- Select proper facing materials of the mechanical seals
- For longer dry running periods, select quenching on double mechanical seals
Twin Screw Pumps (except FMH hygienic pumps, that are self-draining) are designed
to retain some liquid inside the pumping chamber
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SUCTION & NPSH
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Twin Screw Pumps have high suction lift and low NPSHr pumps.
Generally, Centrifugal Pumps have worse suction lift.
If the Fluid Pressure in a major cavity of the pump drops down the vapor pressure, then the liquid will
vapourize (formation of vapor/gas bubbles in the liquid).
The Fluid enters the Pump Suction Flange and, because of frictions and hydraulic effects (changes
of flow, turbulences etc.), the hydrostatic pressure of the fluid drops down.
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SUCTION & NPSH
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SUCTION LIFT PERFORMANCES DEPEND ON:
- PUMP CONSTRUCTION: Geometry of the Chamber and Suction Port
- FLUID VAPOUR PRESSURE: fluids with high vapour pressure need pumps with Lower NPSHr in order to
avoid cavitation
- PUMP SPEED: Higher Speed = Higher Vacuum on Suction = Higher NPSHr
- PUMP CAPACITY: Higher Capacity on the same pump = Higher Hydraulic Losses = Higher NPSHr
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SUCTION & NPSH
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CAVITATION
If the Pressure in any part of the Pump Chamber falls below the Fluid Vapour Pressure, the Fluid will
vapourize (formation of bubbles of gas/vapour inside the liquid).
The implosions are so strong that they can damage the
wetted metallic surfaces of the pumps and create a
particular erosion effect.
The effects of Cavitation may destroy a pump quickly
Cavitation will directly decrese the Pump Performances
On other part inside or downstream of the pump, because of the pumping effect, the fluid pressure will be
over the Vapour Pressure again, and the gas bubble will implode suddenly and become liquid again.
This implosion is very fast and a multitude of collapsing bubbles generates a noise similar to «Cracking»
«Small stones passing inside the piping»
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SUCTION & NPSH
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EFFECTS OF CAVITATION
CENTRIFUGAL PUMPS
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SUCTION & NPSH
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NPSHr = Net Positive Suction Head required
This is the difference between the Pressure at the Suction Flange of the Pump and the Fluid Vapour
Pressure
This is the Minimum Head required by the pump, calculated at the Suction Flange, in order to avoid
Cavitation at a certain Flow Rate and with a certain Fluid.
In order to avoid Cavitation, NPSHa must be higher than NPSHr:
NPSHa = Net Positive Suction Head available
NPSHa > NPSHr
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SUCTION & NPSH
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How to improve (=increase) NPSHa:
Reduction of Friction Losses and Hydraulic Losses:
- Larger Diameter Piping
- Reduction of Piping Elbows
- Smoother rugosity values of the Piping
- Less Valves (or Full Bore Valves)
- Reduction of the Velocity of the Fluid and avoidance of Turbulent Flow
- Avoid changes of diameter of the Piping
- Position of the Pump below the suction tank (example, in an underground Pit)
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SUCTION & NPSH
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- Select a pump with low NPSHr (for example, a Twin Screw Pump)
- Select an optimal geometry of the Pump Suction
- Run the pump at the optimal speed (=not too fast speeds)
- Select a pump slightly oversized for the required flow rate
How to improve (= lower) NPSHr:
Very good realistic values of NPSHr are around 1,5 meters
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SUCTION & NPSH
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Typical Suction Head Curve:
When the capacity loss is
higher than 3%, then it is
assumed that Cavitation has
started
Gas entrained in the liquid
(bubbles) will be degassed:
The Performance Loss is
smoother than in the
Cavitation effect
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – PUMP EXECUTIONS FOR HIGH TEMPERATURES
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- Cooling of the Timing Gearbox and of the
Bearing Housing may be required
- It is recommended to use a longer shaft for
better cooling on the ends
- Cast Casing Pumps with Heating Jacket
- Fabricated Steel Pumps with Welded Heating Jacket
- Pumps with Electric Tracing Coils
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SHAFT DEFLECTION
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It is important to assure high stiffness / rigidity of the shaft costruction, in order to minimize the
deflection
- Short Width and
Compact Pump
- Short Distance between the
Bearings
- High Elastic Module Materials
(high rigidity)
- Less deflection means smaller
clearance between screws
and liner
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – SPEED VARIATION
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Twin Screw Pumps are often operated by motors at fixed speed.
The usage of a Speed Variation Device (for example Variable Frequency Drive) can give some advantages
like:
- Change of Capacity
- Possibility of pumping a wide range of viscosities
- Soft / Smooth Start-Up and Cold Starts
- Improvement of Suction Capability (for example during Stripping)
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – PUMP INSTRUMENTATION
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Twin Screw Pumps can be mounted, on request, with the following accessories:
- Temperature Sensors / Transmitters on Pump Bearings and / or Casing
- Vibration Sensors on Pump Supports
- Valves and Piping
- API PLAN Seal Panels
- Pressure Sensors / Transmitters on Pump Suction and / or Discharge Ports
- Bearing / Gear Boxes Cooling Systems (by water or by air/oil), with natural and
forced re-circulation
- Dry Running Protection (Oil Pot)
- All Motor Options and Executions in accordance to major Suppliers
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – MARINE & SHIPBUILDING
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Twin Screw Pumps for Marine & Shipbuilding:
- Vertical Executions: More common because of space saving;
different executions can be offered;
Non Submerged Versions and Submerged Versions available
- Horizontal Executions (example some Cargo Loading/Unloading, Slops)
The following Class Certification and Inspections are available
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – MARINE & SHIPBUILDING
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VERTICAL EXECUTIONS
Submerged Vertical
Twin Screw Pump
supported by mounting
stool
Submerged Vertical
Twin Screw Pump with
Double Cardanic Shaft
Vertical Twin Screw
Pump, not submerged
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – MARINE & SHIPBUILDING
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PUMP WITH BULKHEAD:
The pump is in an hazardous area
The motor is in a safe area;
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – MARINE & SHIPBUILDING
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Applications for Twin Screw Pumps for MARINE AND SHIPBUILDING:
- Engine Room Pumps
- Cargo Pumps
- Stripping and ballast water Pumps
- Bitumen tanker Pump
- Slops
- Stripping of Tank
ADVANTAGES:
- Ideal for pumping low and high viscosity products and oil&water mixes
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – TANK STORAGE
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Applications for Twin Screw Pumps for TANK STORAGE:
- Pumping high or low viscosity products
- Loading / Unloading with high or low capacity
- Pumping at high or low pressure
- Pumping at high or low pressure
- Circulation from Tank to Tank
- Stripping of Tank
ADVANTAGES:
- Installation of 1 inlet pipe (reduced installation costs)
- Easier operation and higher safety due to variable operation
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – MARINE & SHIPBUILDING
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3 SCREW PUMPS UNDER DEVELOPMENT
THREE SCREW PUMP CAPACITY RANGE
DESIGN
PRESSURE MARKET
MT Series Universal Mid-Pressure Three Screw Pump 50 m3/h 25 Bar Oil&Gas, Industrial, Marine
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – CRITICAL APPLICATIONS
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PROBLEM SOLUTION
Sand Particles Content Replaceable Liner, Hard Coatings
Corrosive Elements
( Salt / H2S and Sulfides / Chlorides) NACE material, Duplex, Superduplex
Gas Content Mech Seals + API PLAN or Multiphase
Toxic Fluids Double Mech Seals + API PLAN 52, 53, 54
Wax, Paraffin Mech seals heating / cold start issues
Hydrocarbons, Aromatic Hydrocarbons Proper Elastomer Material
High Temperatures (example Bitumen, Tar) Heating Jacket, Longer Shaft, cooled gears
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – CRITICAL APPLICATIONS
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PROBLEM SOLUTION
Dry Running Double Seals with Quench, Oil Pot with Sensor
Low NPSHa Right pump selection, optimize speed
High Discharge Pressure Increase Casing Design Pressure (UD, JD)
High Differential Pressure Longer Shafts, Increase Gap with Liner
Low Environment Temperature Low Temp Materials and Lubrication
High Environment Temperature Sunshades, Gearbox Cooling, Derated Motor
High Elevation (Altitude) Motor derating
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – CRITICAL APPLICATIONS
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PROBLEM SOLUTION
API 676 requirements
Separate Relief Valve, Special Materials,
API 682 Seals, API Baseplate
ATEX requirements (Zone 0? Zone 1? Zone 2?) ATEX motor, ATEX Pump
Other Hazardous Area Requirements (UL/FM, CSA) Suitable Motor certification
Multi Pump Skid Package
Clarify the Operational Requirements
and Scope of Supply (Piping, Valves, Sensors, Inverter, PLC)
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – PUMP TESTING
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Our Twin Screw Pumps are 100% tested.
Minimum Testing Standards:
- Casing Hydrostatic Test: 1.5 times the casing design pressure for 10 minutes
- Performance Test at Rated Conditions or at Re-calculated Conditions with Test Fluid Viscosity –
Standard VDMA 24 284
- Functional Running Test (no load) for checking Accessories Functionality (when included)
Other Testing Standards:
On request, we can perform tests in accordance to the major Standards
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – PUMP TESTING
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VDMA 24 284 Standard
Permissible deviations for the capacity
According to the Standard VDMA 24284, the reading of the capacity value performed with the
instrument may deviate from the contract value according to the following values:
Q (l/h) ≤100 +20% / -10%
100≤ Q (l/h) ≥1000 ±10%
Q (l/h)>1000 +10% / -5%
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – PUMP TESTING
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VDMA 24 284 Standard
Permissible deviations for the power
According to the Standard VDMA 24284, Table 5, Group 2, the reading of the power value performed
with the instrument may deviate from the contract value according to the following values:
P (kW) ≤5 +25%
5≤ P (kW) ≥10 +20%
10≤ P (kW) ≥50 +15%
P (kW)>50 +10%
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – PUMP TESTING
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API 676 Standard
- Permissible deviations for the Capacity:
Tolerance at 100% speed : +3% / -0%
- Permissible deviations for the Power:
Tolerance at rated pressure + capacity: +4%
- Permissible deviations for the NPSHr:
Tolerance at rated capacity: +0%
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – API 676 STANDARD
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Our Twin Screw Pumps can comply with API 676 Standard (2nd and 3rd edition) on request
Some of the most important design conditions requested by API 676:
- Relief Valve shall be external (we generally supply it «loose»)
- Baseplate shall be provided with lifting lugs, earthing bosses, levelling screws;
it shall be suitable for grouting,
it shall extend below the drive train components and accessories,
and drain pipe shall extend up to baseplate edge
- Mechanical seals shall be API 682, with suitable API PLAN as applicable
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – API 676 STANDARD
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MAIN EXCEPTIONS / DEVIATIONS POSSIBLE FROM API 676 3RD ED.
PARA 6.9.4 (Last Sentence)
Depending on the interaxis lenght between the 2 axis, there may not be sufficient space to assemble 2
API 682 Cartridge Seals;
API 676 accepts that Cartridge type seals should be used when not unpractical:
“NOTE: Space or design parameters for some pump types, sizes, or applications make the use of API
682/ISO 21049 seals impractical”
SO THIS IS AN ACCEPTABLE DEVIATION FOR SMALL SIZE PUMPS (HD06, HD07, HR09, HR14)
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – API 676 STANDARD
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MAIN EXCEPTIONS / DEVIATIONS POSSIBLE FROM API 676 3RD ED.
PARA 6.8.2.1
Timing Gears of the Twin Screw Pump will be designed as per ISO Standards, not as per AGMA
Standard.
PARA 6.8.1.9
Rotors for twin screw pumps shall be dynamically balanced to ISO 1940-1 Grade 2.5.
We generally propose Grade 16 in order to avoid costly calibration or more expensive double profile
screws.
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – API 676 STANDARD
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MAIN EXCEPTIONS / DEVIATIONS POSSIBLE FROM API 676 3RD ED.
PARA 6.12.9 and 6.12.10
Pressure lubrication system for Timing Gear Box and Bearing Housing is not generally to API 614,
unless explicitally required (because of the major price impact)
PARA 6.1.1.
Uniterrupted years of operation does not generally exceed 2 years (instead of the 3 years required)
because of Mechanical Seals Service Life
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – API 676 STANDARD
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MAIN EXCEPTIONS / DEVIATIONS POSSIBLE FROM API 676 3RD ED.
PARA 7.5.1 and 7.5.2
Pressure Limiting Valves (Relief Valves), in downstream applications, may be supplied not fully as per
API 520 and 526 standards.
PARA 6.13.2.1.
API 676 requires that «Unless otherwise specified, the materials of construction of the pressure-
containing casing shall be carbon steel as a minimum».
When technically possible, we propose as alternative Cast Iron Casing, unless Carbon Steel is
specifically required on the Data Sheets.
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS – API 676 STANDARD
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MAIN EXCEPTIONS / DEVIATIONS POSSIBLE FROM API 676 3RD ED.
PARA 8.3.6
Test Tolerances proposed are in accordance with VDMA 24 284 Table 5 group 2.
PARA 8.2.2.1.1
Radiographies are not offered, in case Purchaser request for them.
As alternative, we propose other NDE tests.
3P Prinz Pump Manufacturing Company
PERA-PRINZ® TWIN SCREW PUMPS
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END