Full Hot Tap

What are the pipeline details?

MaterialCarbon Steel/Stainless/Cast all affect the choice of cutters andpilots.

SizeThe pipe size and wall thickness have an affect on the choice ofpilot and cutter for swarf clearance.

Fittings The size of the fittings and valve affect the overall reach requirements of the hot tap drilling machine, and therefore the choice of machine.

PressureThis decides what adapter is to be used and subsequently the Maximum Allowable Operating Pressure.

Temperature This effects the machines seals and therefore the Maximum Allowable Operating Temperature. Cooling spools can be used to reduce the temperature at the machine.

What are the pipeline details?

Product The nature of the product and its chemical constituency can effect the pressure and temperature rating. If it is corrosive then it may also affect the safe operation of the equipment.

Tap sizeThe size of the tap has a direct bearing on the choice of tapping machine and will determine, together with the header size, the overall reach required to carry out the hot tap.

Pipeline Content

FlammableIs the product flammable? If so, the installation should be purged with inert gas.

ToxicSpecialist procedures required. Provide adequate precautions for the protection of personnel during operation and disposing of product in Tapping Machine Adapter.

CorrosiveSpecialist procedures required (Refer to Hot Tap specialist)

Inert Take precautions in accordance with Chemical requirements of product.

Very Corrosive Products

What can you hot tap into ?

Very High Temperatures

Non Standard Taps

Off-Set TapAngle Tap

Bend Tap

Blind Tap

Hot Tap Orientation

Standard vertical tap - no unusual problems

Hot Tap Orientation

Angled vertical tap - no problems for angles less than 45 degrees

Hot Tap Orientation

As the angle of tap rotates around there becomes more chance of the swarf from the tap coming back towards the valve and the tapping machine adapter resulting in problems closing the valve and withdrawing the cutter fully.

Hot Tap Orientation

The measuring rod will tend to fall out. It is also considerably harder to install the drilling machine into position.

Clearance for Hot Tap

Longitudinal weld accessrestricted by adjacent pipes

Longitudinal weld location at an alternative position in order to improve weld access

X

Y

Not just X and Y but how to get the machine into position

Clearance for Hot Tap

Temperature

Maximum Temp700 deg F @ 700 P.S.I.(371 deg C @ 48 bar )

Normal maximum operating pressure1440 P.S.I.

Flow Rates

Gas - 10 m/s - 30 fps - 20 mphLiquid - 5 m/s - 15 fps - 10 mph

Standard U-Wire Pilot Drill

Gas and Liquid unlimited.Fastest to date - 60 m/s - 180 fps - 120 mph

Positive Retention Pilot Drill

Up to 3” Hand / Air

2” to 6” Air / Hydraulic

3” to 12” Air / Hydraulic

4” to 16” Hydraulic



Drilling Machine Power Source

Distance to face of valve

X

Y-Z

Position A

Distance for Position A(Ready to start hot tap)

= X+Y-Z

Tapping Distance

PER

Distance for cutter to complete tap

pir

CER

W

Distance for cutter to complete tap =W

W= PER- (pir - CER )2 2

PER

Distance for cutter to complete tap

pir

CER

W

Distance for cutter to complete tap =W

W= PER- (pir - CER )2 2

PER = 200mmpir = 185mmCER = 150mm

W= 200 - (185 - 150 )2

W= 200 - (34225 - 22500)

W= 200 - 11725

W= 200 - 108.28W= 91.72mm

2

Pilot Distance (V)

Tapping Distance

= V + W

Note V+W < PER+pir

Pilot Distance (V)

Once cutter through by calculated measurement, machine should be stopped and cutter advanced to confirm tap completed.

Coupon retainedby ‘U’ Wire

Coupon and cutterare withdrawn

Full Hot Tap

Documents

Transcript of Full Hot Tap