Cashco 31-B - Manual

IOM-31-B
05-14
MODEL 31-B
Back Pressure Relief Service Regulator
SECTION I
II. INSTALLATION
1. An inlet block valve should always be installed.
2. If service application is continuous such that
shut down is not readily accomplished, it is rec om-
mend ed that an outlet block valve and a manual
bypass valve be installed. Refer to Figure 1.
3. Pipe unions are recommended to be installed to
allow removal of this unit from piping. Trim can
be changed without removal from pipeline.
4. An inlet pressure gauge should be located ap-
prox i mate ly ten pipe diameters upstream, and
within sight.
5. All installations should include an upstream
re lief device if the inlet pressure could exceed
the pressure rating of any equipment or the
maximum inlet pressure rating of the unit.
SECTION II
I. DESCRIPTION AND SCOPE
The Model 31-B is a back pressure relief service regulator used to control upstream (inlet or P
1
) pressure to
levels between 2–16 “WC (50–400 mm H
2
O). Sizes are 1/2", 3/4”, 1", 1-1/2" and 2" (DN15, 20, 25, 40 and 50).
The unit is designed for gaseous service only.
Refer to Technical Bulletin 31-B-TB for sizing, application and selection recommendations.
INSTALLATION, OPERATION & MAINTENANCE MANUAL (IOM)
CAUTION
1. This is not a safety device and must not be substituted for a code approved pressure safety relief valve or rupture
disc.
2. IF GAS IS DETECTED BY SMELL, CONTACT YOUR GAS COMPANY IMMEDIATELY.
3. User to comply with instructions, operating re quire ments & maintenance requirements located herein the “IOM-31-B”.
CAUTION
Installation of adequate overpressure pro tec tion is rec-
ommended to pro tect the reg u la tor from overpressure
and all up stream equip ment from damage in the event
of regulator failure.
CAUTION
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.
6. Clean the piping of all foreign material including
chips, welding scale, oil, grease and dirt before
in stall ing the regulator. Strainers are rec om-
mend ed.
7. In placing thread sealant on pipe ends prior to
en gage ment, assure that excess material is
re moved and not allowed to enter the regulator
upon startup.
8. Flow Direction: Install so the fl ow direction
match es the arrow cast on the regulator body.
9. Regulator may be rotated around pipe axis 360°,
and may be installed in a horizontal or vertical
pipeline. Two orientation/arrangement assembly
positions are standard. Orient to prevent the
upper case vent hole from collecting rainwater
or debris. Reorient ac tu a tor around the stem
axis 360° if nec es sary. Refer to Figure 2.