Pressure Control Liquid Level Control Temperature Control Glycol Pump Control Valves.
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Transcript of Pressure Control Liquid Level Control Temperature Control Glycol Pump Control Valves.
Pressure Control
Liquid Level
Control
Temperature
Control
Glycol Pump
ControlValves
Temperature Controllers
Indirect Thermostat
T12
Negative feedback forlinear output 5 to 30 psi air or
gas supply pressure
Stainless steel housing
Bi-metal sensing elementfor accurate control
Output pressure proportionateto temperature at any setting
Single adjustment overWide temperature range: T 12 -30 to 400oF HT 12 -30 to 700oF
? Direct or Indirect ?
Direct Mode Indirect Mode
Rising Temperature Rising Temperature
Rising Output Falling Output
Direct Indirect
Indirect Thermostat
Indirect
Thermostat with Separable Socket
Maximum Working Pressure
Without Separable Socket 500 psiWith Separable Socket 4000 psiWith Special Separable Socket 7000 psi
Direct Acting Thermostat
T 12DASupply Output
Direct
T 12DA Thermostat
Output
Supply
Indirect
Reversed for Indirect Throttle Mode
High Temperature Thermostat
HT 12Output
Supply
Indirect
Direct Snap Thermostat
T 12S
OutputSupply
Direct
Indirect Snap Thermostat
T 12DASOutput
Supply
Indirect
Indirect Throttle Thermostat
T 12T
Output
Supply
Indirect
Direct Throttle Thermostat
T 12TDA
Output
Supply
Direct
Direct Semi-Throttle Thermostat
T 12DAT
Output
Supply
Direct
Indirect High Temperature Shut-Down
T 12MOutput
SupplyIndirect
Direct Low Temperature Shut-Down
T 12DAM
Output
SupplyDirect
High Temperature Pilot Guard
HT 12PG
Output
Supply
Direct
Typical Installation
High temperatureshutdown thermostat
Burner controlthermostat
Safety shutdown
valve
Burnervalve
Main burner
Pilot
Pilot GuardthermostatInstrument Gas
High temperatureshutdown thermostat
Burner controlthermostat
Safety shutdown
valve
Burnervalve
Main burner
Pilot
Pilot Guardthermostat
Instrument Gas
Low liquid shutdown pilot
Typical Burner Control Installation
Trouble Shooting
SYMPTOM CAUSE
• Erratic temperature changes
•Continuous venting
• Bent sensing element (element should be centered in base and should “ring”)
• Incomplete immersion of probe
•Dirty pilot plug seat•Hole in diaphragm•Weak pilot plug spring•Faulty ‘O’ ring
Trouble Shooting
• To check small seat: increase temperature setting several degrees and see if venting stops.
• To check large seat: decrease temperature setting several degrees and see if venting stops.
• Replace pilot plug and seats if unable to stop venting by cleaning seats.