2. A Pressure Reducing Valve is a
self contained, automated
regulating device for controlling
the pressure of a fluid at a
constant value lower than the
higher pressure source without
the use of external power.
3. Regulator Designs
• Spring loaded - Direct operated
• Pilot operated
Diaphragm Pilot
Piston Pilot
• Pneumatic operated
4. Regulator accuracy*
• Direct operated 75%
• Internal or external pilot 80-99%
• Air loaded 95%
*Consult manufacturer
5. Points to consider
• Rangeability
• Droop or offset
• Failure position
• Accuracy
• Steam quality
• Constant or intermittent
• Noise
6. Droop & Accuracy of Regulation
• Offset from the set point between the
minimum and maximum flow as a percentage
of the set point
• Example: Set point=100 PSIG, pressure at
maximum flow =75 PSIG…
• Droop = (100-75)/100 = 25% Offset (droop)
as a percentage of the set point
• Accuracy Example: Set point 100 PSIG,
pressure at max flow = 75 PSIG
• Accuracy = 75/100 = 75%
7. 62
60
58
64
56
54
52
50
48
1000 2000 3000 4000 5000
Capacity v. Regulation
Steam Flow (#/hr)
Leslie GPKP
Fisher 92B
Masonelian 220-22
Spence ED
2 inch Valves
100 psig Inlet
60 psig Set Point
8. Rangeability
• The ratio of minimum flow to
maximum flow where the valve will
maintain stability, operate within
specified accuracy
12. Leslie No Maintenance Solution - GPK
• No pilot, large clearances
No tiny parts or orifices to clog
Dirty steam no problem
• Air loader PSI
Must be > P2 (outlet) PSI
Plant air or point-of-use
compressor
• CI or bronze body; GPS &
GPHS available in Steel &
SS
• Very reliable, 3 yr warranty
13. Leslie’s Spiroflex Diaphragm
• Formed Spiroflex diaphragm
Holds shape, prevents metal
fatigue and kinks
• Extends service life.
• Fast acting - high capacity
• Responds to pressure
changes of 0.1 psi or less
14. Air Loaded GPAK
• Elastomeric diaphragm
• For hard to hold gases and
vapors
Helium, nitrogen, butane, CO2
Nitrogen, air, natural gas
• Up to 400 PSI inlet
• 0-120 PSI outlet
• 180F max
15.
16. Leslie Solution: GPKP
(Integral Pilot)
• Ports with large clearances
ABOVE main line
Protected from dirt
Pilot doesn’t use steam
continuously=less dirt carry over
• Integrally top mounted pilot
Pre-piped for lower installed cost
Fewer connections/leak paths
Accessible from either side
• 3 year warranty
18. Class GPKP
• Cast Iron Construction
• Three Interchangeable
Springs
• Patented Dual Diaphragm
Pilot
• OK for poor quality steam
• Rangeability:100:1
• Accuracy:95%
19.
20. Leslie GPS-1 EP
• Allow use of GPS-1 Series where self operated is required
• Priced above GPS-1 with air loader
• Priced below steel piston balanced “L” Series
• Rangeability: 30:1
• Accuracy: 80%
21. • Allows use of GPS-1 Series
(steel body GPK) where self
operated is required
• Priced above GPS-1 with air
loader
• Priced below steel piston
balanced “L” Series
• 30:1 rangeability
• 80% accuracy of regulation
Externally Piloted GPS-1EP
22. • Steam, air or gas service
• 1/2” threaded ends only
• Bronze construction
• Higher capacity & more
accurate than “LC” regulators
• Not for dirty steam or
intermittent service
• 10:1 Rangeability
• Accuracy of regulation 85%
Diaphragm Operated J Series
23. • Cast iron, bronze or steel
body
• Steam and gas service only
• 99% Accuracy of
Regulation
• P1-P2 differential must >15
PSI
• Not for dirty steam or
intermittent service
• 10:1 rangeability
Piston pilot operated LKY Series
24. • Small flows
Steam, air, gas, liquids
4 outlet ranges
½” Connections
• Available bronze or steel
Bronze -- 400 PSI max inlet,
300 PSI steam
Steel – 1000 PSI max inlet,
600 PSI steam
• 10:1 rangeability; 25%
droop
Direct Operated LC Series
25. Problem: Why does the safety open?
• Existing regulators are
unstable
Loading pressures gain &
outlet pressures droop as
flows/system loads
increase
Outlet pressures flows
creep up as flows
decrease
• Regulators cycle on & off
26. Problem: Low Turndown
• Other regulators typically max out at 10 to 1
• Two regulators are recommended*:
“When normal conditions require operation at
10% (or less) of specified maximum capacity for
sustained periods”
“When there are two distinct load conditions (i.
e. summer/winter operation.)”
*Spence Pressure Reducing Station Design Guidelines, page
E6
27. Leslie GPK/GPKP Solution: 100:1
Turndown
• Two-stage or parallel piped 1/3-2/3
systems often NOT needed
• Use a single regulator!
• Hardened SS & Stellited seats
Take the throttling -- don’t develop leaks.
• This is really a
“control valve in a regulator’s
body”
28. GPKP Competitive Comparison
Characteristics Leslie GPKP
Fisher 92B
"Competitor A"
Masoneillan 220-22
"Competitor B"
Spence
"Competitor C"
Accuracy of Regualtion Excellent Good Fair Poor
Capacity at 1 PSI Droop 100% 96% 66% 28%
Reduced Pressure Range
(PSI)
1-150 PSI
3 springs, 1 integral
pilot assembly
2-150 PSI
6 Springs, 2 pilots
2-150
3 Springs, 1 Pilot
3-150
4 Springs, 1 Pilot
Range Change: Adjusting
Spring. Case removal
Required?
No Yes Yes
No (unless optional
enclosed spring case
purchased)
Minimum Press Drop
Across Valve at Full
Capacity
10 PSI
20 PSI, 10 PSI available
with extra cost inconel
spring option
20 PSI Minimum; 25 PSI
Recommended
10 PSI Standard; Lower
DP Available at Extra
Cost
Pilot & Valve Fully
Assembled?
Yes Yes Yes NO
Stability at Varying Press.
Drops
Excellent Good Good Fair
Seat Ring
Seat Ring Material
Hardened SS Hardened SS SS Brass with SS Insert
Diaphragm
Stainless Steel with
Spiroflex Design
SS SS SS
Warranty 3 Years 1 Year 1Year 1 Year
31. Small Regulator Ports
& Loose Tubing
• Easy to plug
• Water carries dirt
• Maintenance
headache
32. What causes typical early
problems?
• Small ports in fittings or pilot valve
• Dirt in system during installation and
fabrication
Weld slag
Cigarette butts
Mice and bugs
• Complex field-assembled pilot tubing
33. Typical Regulator Problems
• Dirt in pilot bleed ports
• Leaky, improperly installed pilot tubing
• Safety popping or “weeping”
• Blown diaphragms
• Poor control; wire drawn seats
