cashco 1171 Installation, Operation & Maintenance Manual

ISO Registered Company

I. DESCRIPTION AND SCOPE

Models 1171 and 2171 are back pressure/relief regulators used to control upstream (inlet or P
1/4", 3/8" and 1/2" (DN8, DN10 and DN15). The 1171 is a bronze bodied unit; the 2171 incorporates a stainless steel
body. With proper trim utili za tion, both units are suitable for liquid, gaseous and steam service (the 2171 can also
be used with various chemi cals). Refer to Tech ni cal Bul le tins 1171-TB and 2171-TB for specific design conditions
and selection rec om men da tions.
The instructions in this manual will refer to both models, unless otherwise stated.

II. INSTALLATION

For welded installations, all internal trim parts, seals and
diaphragm(s) must be removed from reg u la tor body prior
to welding into pipeline. The heat of fusion welding will
dam age non-metallic parts if not re moved. NOTE: This does
not apply to units equipped with extended pipe nip ples.
1. An inlet block valve should always be in stalled.
2. If service application is continuous such that
shut down is not readily accomplished, it is rec-
ommended that an inlet block valve, outlet block
valve, and a manual bypass valve be installed.
3. Pipe unions should be installed to allow removal
from piping.
4. An inlet pressure gauge should be located
ap proxi mately ten pipe diameters upstream, and
within sight. An outlet pressure gauge is op tion al.
The maximum inlet pressure is equal to 1.5 times the
larger number of the stated range spring on the name-
plate, and is the rec om mend ed "upper op er a tive limit" for
the sens ing diaphragm. Higher press ures could dam age
the di a phragm. (Field hydro static tests fre quent ly destroy
dia phragms. DO NOT HYDRO STATIC TEST THRU AN
IN STALLED UNIT; ISO LATE FROM TEST.)
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
MODELS 1171 AND 2171
BACK PRESSURE / RELIEF REGULATORS
This is not a safety device and must not be sub sti tut ed for a code
approved pressure safety relief valve or rupture disc.
CAUTION
CAUTION
SECTION I
CAUTION
SECTION II
Supply
@ P 1
P
1
Dis charge
Recommended Piping Schematic For Back Pressure/Relief Station
5. All installations should include an upstream relief
device if the inlet pressure could exceed the
pres sure rating of any equip ment or the max i mum
inlet pressure rating of the unit.
6. Clean piping of all foreign material including chips,
welding scale, oil, grease and dirt before installing
the regulator. Strainers are recommended.
7. In placing thread sealant on pipe ends prior to
engagement, assure that excess material is
re moved and not allowed to enter regulator upon
startup.
) pressure. Sizes are
1
SRV
Models 1171/2171
BP/Relief Regulator
P
1
IOM-1171/2171
02-16
System
P
2