111
P a r r I n s t r u m e n t C o m p a n y
1 - 8 0 0 - 8 7 2 - 7 7 2 0
5
O p t i o n a l F i t t i n g s
Pressure Relief Valves
Gages
2633HCP10AD 3-1/2" Back Mount Gage
593HCPF Gage
3-1/2" Dia.
56HCPF Gage
4-1/2" Dia.
S
pring-loaded relief valves should be viewed
as supplements and not substitutes for a
safety rupture disc which is the primary means
protecting the vessel and the operator in case
of accidental over-pressure. Spring loaded relief
valves can be added to a reactor or vessel to:
• Relieve
pressures near the maximum
operating pressure.
• Reseal
once excess pressure has been
relieved.
• Protect
low pressure components at pres-
sures below available rupture disc ranges.
The relief valves listed below can be installed
on any Parr vessel. These relief valves are
stainless steel and have FKM O-rings. Other
valves and O-ring materials are available on
special order.
A175VB
Relief Valve
Pressure Relief Valves
Part No.
Relief Pressure
Range, psi
Discharge
Connection
A140VB2PA
50-150
1/4" NPT (M)
A140VB2PB
150-350
1/4" NPT (M)
A140VB2PC
350-600
1/4" NPT (M)
A175VB
750-1500
1/4" NPT (F)
A175VB2
1500-2250
1/4" NPT (F)
A175VB3
2250-3000
1/4" NPT (F)
A175VB4
3000-4000
1/4" NPT (F)
A175VB5
4000-5000
1/4" NPT (F)
Note: When ordering any of the above relief valves,
the user may specify a desired set pressure.
G
ages for Parr pressure
vessels can be furnished
with either 3-1/2" or 4-1/2" dials
in any of the ranges shown in
the table below. All have stain-
less steel Bourdon tubes and
1/4" NPT male connections.
Alloy 400 gages are
available on special order.
Accuracy is .5 percent of full
scale for the 4-1/2" size and 1
percent for the 3-1/2" gages.
All are calibrated in both
Gages
Pressure,
psi
Range,
bar
4-1/2" Dia.
Gage No.
3-1/2" Dia.
Gage No.
3-1/2" Dia. Back
Mount Gage No.
0-100
0-14
56HCPA
593HCP1AD 2633HCP1AD
0-200
0-28
56HCPB
593HCP2AD 2633HCP2AD
0-600
0-40
56HCPC
593HCP6AD 2633HCP6AD
0-1000
0-70
56HCPD
593HCPD
2633HCP10AD
0-2000
0-137
56HCPF
593HCPF
2633HCP20AD
0-3000
0-210
56HCG
593HCPG
2633HCP30AD
0-4000
0-280
NA
593HCP40AD —
0-5000
0-350
56HCPH
593HC50AD —
0-7500
0-517
56HCP75AD NA
—
0-10000
0-700
56HCPK
NA
—
30" Hg Vac/300 psi
56HCP3YB 593HCP3YB 2633HCP3YB
pounds per square inch (psi)
and bars. Gages in Pascal
units are available on special
order. Compound gages which
show vacuum to 30 inches of
Mercury and positive pressures
to 300 psi (20 bar) are also
available.
When ordering a special
gage, specify the gage diam-
eter, the desired range and
scale units.
The gage on a pressure
vessel should be 150 percent
of the maximum operating
pressure. This allows the gage
to operate in the most accurate
pressure range and prevents
the gage from being stressed
repeatedly to its full range,
which will effect the calibration.
