Data Sheet

Bulletin 71.4:1808
2
• —With the removal of just two
nuts, the upper and lower casings lift away, exposing
the trim and leaving the main valve body in the line.
• 
 —For gas service with the Type 6358B
pilot, upstream control line construction is available
to provide wide-open relief ow capacity with less
buildup regardless of set pressure.
• —The Type 1808A angle-body
design has increased capacity and provides
complete process uid drainage from body cavity
during shut-down period or before disassembly of
the main valve.

The Specications section gives some general
specications for the 1808 Series Pilot-Operated Relief
Valves or Backpressure Regulators. The nameplates
give detailed information for a particular regulator as it
comes from the factory.


 See Table 1

2 NPT


150 psig (10,3 bar) including buildup

See Table 2

 125 psig (8,6 bar)
 5 psig (0,34 bar)

Bleeds only when repositioning the main valve

Continuously bleeds while inlet pressure is above
set pressure

See Table 3

See Tables 4 and 5 and Capacity Information section

Internal  or External (optional)

1/4 NPT with or without P590 Series lter


-20° to 180°F (-29° to 82°C)

 
Type 1808 Body: Cast iron or WCC Steel
Type 1808A Body: Cast iron
Diaphram Plates and Diaphragm Casings:
Zinc-plated steel
Diaphragm: Neoprene (CR), Nitrile (NBR)

O-Rings: Nitrile (NBR)
Gaskets: Nitrile (NBR)
Back-up Rings: Polytetrauoroethylene (PTFE)
Spring: Zinc-plated steel 
Valve Plug Guide: Stainless steel
 
Body: Aluminum or CF8M Stainless steel
Spring Case: Aluminum or Stainless steel
Body Plug: Aluminum or Stainless steel
Valve Plug: Nitrile (NBR) or thermoplastic
plug with stainless steel stem
Spring: Zinc-plated steel
Diaphragm: Nitrile (NBR) or Fluorocarbon (FKM)
Spring Seat: Zinc-plated steel
Stem Guide: Stainless steel
Adjusting Screw: Zinc-plated steel
O-Rings: Nitrile (NBR) or Fluorocarbon (FKM)
Closing Cap: Plastic or Stainless steel
Connector Cap: Stainless steel
 
Tubing: Stainless steel
Fittings: Steel or Stainless steel
Pipe Tees: Galvanized steel
Pipe Nipples: Malleable Iron, Galvanized Steel,
and Stainless Steel

• Upstream control line construction
• Pressure gauge (0 to 160 psig/0 to 11,0 bar/
0 to 1,1 MPa)
• P590 Series Pilot Supply Filter

 22 pounds (10 kg)
 25 pounds (11 kg)
1. The pressure or temperature limits in this Bulletin and any applicable standard or code limitations should not be exceeded.