Instruction Manual

Types 1808 and 1808A
2


2 NPT


150 psig (10,3 bar) including buildup

See Table 1

 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 2

Internal  or External (optional)

1/4 NPT with or without P590 Series lter



-20° to 180°F (-29° to 82°C)

 22 pounds (10 kg)
 25 pounds (11 kg)

• 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
1. The pressure/temperature limits in this Instruction Manual and any applicable standard or code limitation should not be exceeded.
Table 1. Types 6358 and 6358B Set Pressure Ranges, Pressure Ratings, and Pilot Spring Information
Table 2. Types 1808 and 1808A Flow Coefcients



 




3 to 18
15 to 40
35 to 125
(0,21 to 1,2)
(1,0 to 2,8)
(2,4 to 8,6)
1B986027212
1E392527022
1K748527202
Green
Yellow
Red
0.120
0.148
0.192
(3,05)
(3,76)
(4,88)
2.12
2.00
2.19
(54,0)
(51,0)
(55,6)
the oil and gas industry are typically handled by the
Type 6358B pilot. With either pilot, the set pressure
is varied to individual requirements by the adjusting
screw on the pilot. Pilot exhaust can be piped into the
downstream line or vented into the atmosphere on gas
service and should be piped downstream or to a safe
location on liquid service.

The Specications section provides ratings and
specications for Types 1808 and 1808A relief
valves or backpressure regulators. Some of the
specications for a given unit as it comes from the
factory appear on the nameplate attached to the upper
diaphragm case. The Type 6358B pilot restriction
diameter is indicated by a letter stamped on the
bottom of the pilot body next to the tapped side outlet:
an H for the yellow high-gain restriction and an L for
the blue low-gain restriction. The pilot spring range
appears on the pilot spring case.

A pressure relief valve is a control device that opens
to relieve uid to atmosphere during an overpressure
occurrence. A backpressure regulator is a control
device that maintains a constant upstream pressure
throughout a given ow range. It functions in the same
manner as a relief valve that opens on increasing
upstream pressure. 




K

C


C

C

X
T
F
D
F

1808 1410 40.1 0.79 35.2 0.78 0.50 0.89
1808A 1800 51.4 0.76 35.0 0.78 0.50 0.87