Leslie Controls GP Pressure reducing valve - Manual (Page 7)

Page 7
GPK-1T, GPK-2TC, GPK-2T AND GPK-4T
PRESSURE REDUCING VALVES SIZES
1 ⁄
2
" THROUGH 4"
HOW TO IDENTIFY YOUR VALVE TYPE
GPK-1 T— Fitted with three (3) stainless steel diaphragms.
GPK-2T—This is a converted GPK-1T fitted with a SUPER-
FLEX diaphragm and a metal spacer ring to control diaphragm
crush.
GPK-4T— As” - 1As” sizes only with Super G body design and
resilient seat.
NOTE: If you wish to take advantage of the long-life
expectancy of the new SUPERFLEX diaphragm, your
GPK-1T can be easily converted to either a GPK-2TC or
GPK-2T during your valve maintenance period.
DISASSEMBLY
1. Remove bolts and nuts from diaphragm cover and lift off
cover. Take out diaphragm(s) and diaphragm disc.
Remove spacer ring if used.
2. Remove bottom cap and bottom cap gasket, main valve
and spring.
3. To remove seat ring, place seat ring wrench over lugs of
ring and strike end of wrench with a hammer several
times while holding wrench in place to loosen seat ring
for removal.
4. Clean diaphragm disc, diaphragm cover and main body
diaphragm seating surface including the rounded portion
below diaphragm face. Cleaning is important as a
diaphragm life can be decreased if diaphragm is allowed
to flex over any rough or scaled areas. A rotary wire
brush is excellent for cleaning these surfaces. Check
diaphragm cover air connection making sure it is not
plugged.
5. Clean and polish seat ring threads and flat face, bottom
cap gasket face and threads, main valve guide in main
body and main valve guide bushing in bottom cap
(Bottom cap bushings are removable in 1/2” through 2”
sizes). To polish main valve and guides, place them in a
lathe and spin rapidly. Use 320 Aluminum Oxide cloth
as polishing agent.
6. After cleaning check all parts for erosion or damage.
Replace if necessary.
7. Use a rotary wire brush and clean main body seat ring
face and threads. Check for any erosion or damage to
threads or flat face. All deposits must be removed from
flat face as a metal to metal steam seal must be
obtained between ring face and main body. Check bot-
tom cap gasket face of main body. Gasket face must be
flat and square; minor nicks should be removed with fine
emery.
8. Blow out all loose scale etc. from body with air.
ASSEMBLY
1 Use a light coating of Never-Seez or similar lubricant on
the first two threads only of seat ring. Blue in seat ring
before final tightening making sure there is full, all-
around contact between seat ring and main body flat
faces. Tighten seat ring to 150 foot pounds torque.
Install main valve guide and tighten.
2. FOR ALL-METAL SEATS ONLY: Place a small amount
of extra fine lapping compound (Carborundum Grade
CF) evenly spaced on main valve seating surface and
lightly lap valve to seat ring. Remove all traces of com-
pound from parts before reassembly.
For TROUBLE FREE OPERATION and TIGHT SHUT-OFF
carefully follow the MAINTENANCE PROCEDURES outlined in this INSTRUCTION.
Diaphragm Cover
Crush Limit Ring
Diaphragm(s)
Diaphragm Disc
Main Valve Guide
Seat Ring
Main Valve
Main Valve Spring
Bottom Cap Gasket
Bottom Cap
Bolt
Nut
*Travel Stop
Bottom Cap Guide
*1/2” through 2” GPK-2TC and GPK-2T do not have a travel stop.