
Principle of Operation
Refer to Figure 2. Inlet pressure registers beneath the
diaphragm. As long as the inlet pressure is less than
the set pressure, spring force causes the lever to hold
the valve closed. When the inlet pressure exceeds
the set pressure, the diaphragm moves to compress
the spring and the lever opens the valve allowing
inlet pressure to bleed into the downstream line or to
atmosphere until the inlet pressure returns to
set pressure.
Installation
The Type 630R relief valve may be installed in any
position. However, the outlet connection and vents
• Low-Pressure
• High-Pressure
NPS 1 and 2 / DN 25 and 50
NPT, CL150 RF, CL300 RF, or CL600 RF
(1)
66 psig / 4.6 bar
550 psig / 37.9 bar
25 psig / 1.7 bar
250 psig / 17.2 bar
(1)
See Table 1
Internal
1/2-inch / 13 mm
216.0
v
: 8.18
1
26.4
F
d
0.50
F
l
0.89
X
t
0.441
(1)
-20° to 180°F / -29° to 82°C
0° to 300°F / -18° to 149°C
Cast iron or steel
Cast iron or steel
Brass or Stainless steel
Brass or Stainless steel
Brass or Stainless steel
Neoprene (CR) or Fluorocarbon (FKM)
Zinc-plated steel
Stainless steel
Plated steel
Steel
Copper with Brass trim or
Stainless steel with Stainless steel trim
Composition
Zinc-plated steel
Aluminum (low-pressure) or
Zinc (high-pressure)
1/4 NPT
Option
• Polytetrafluoroethylene (PTFE)
diaphragm protector
1. The pressure/temperature in this Bulletin and any applicable standard or code limitation should not be exceeded.
must be protected against the entrance of rain, snow,
insects, or any other foreign material that may plug the
outlet or affect the opening and closing of the valve.
If it is necessary to pipe away the outlet, remove the
outlet screen (if one is present).
Flow through the valve must be as indicated by the
ow direction arrow on the body. For dimensional
information see Figure 3.
Fisher
®
provides an instruction manual with every
valves shipped. Refer to this for complete installation,
operation and maintenance instructions. Included is a
complete listing of individual parts and recommended
spare parts.
Bulletin 71.4:630R
2
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