Cashco 6987 - Manual

II. INSTALLATION
IOM-6987
12-13
MODEL 6987
BACK PRESSURE / RELIEF REGULATOR
SECTION I
I. DESCRIPTION AND SCOPE
The Model 6987 is a back pressure relief regulator used to control upstream (inlet or P
1
) pressure. Sizes are 1/2" and
3/4" (DN15 and 20). With proper trim utilization, the unit is suitable for air, inert gases, water, fuel oil and chemicals.
The Model 6987 is not normally utilized in steam service. Refer to Technical Bulletin 6987-TB for design conditions
and se lec tion rec om men da tions.
SECTION II
6. Clean the piping of all foreign material in clud ing
chips, welding scale, oil, grease and dirt before in-
stall ing the valve. Strain ers are rec om mended.
7. In placing thread sealant on pipe ends prior to
en gage ment, ensure that excess material is re-
moved and not allowed to enter the valve upon
startup.
8. Flow Direction: Install so the fl ow direction match-
es the arrow cast on the body. The body has an
angle con fi g u ra tion with a side inlet and bottom
outlet.
9. Regulator may be installed in a vertical or hor i -
zon tal pipe.
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-
om mended that an inlet block valve, outlet block
valve, and a manual bypass valve be in stalled.
3. Pipe unions should be installed to allow removal
from piping.
4. An inlet pressure gauge should be lo cated ap-
proxi mately ten pipe diameters upstream and
within sight. An outlet pres sure gauge is op-
tional.
5. All installations should include an upstream relief
de vice if the inlet pressure could exceed the pres-
sure rating of any equipment or the maximum inlet
pressure rating of the unit.
Recommended Piping Schematic for
Back Pressure/Relief Station
INSTALLATION, OPERATION & MAIN TE NANCE MANUAL (IOM)
CAUTION
This is not a safety device and must not be substituted for a code approved pressure safety relief valve or a rupture disc.
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.
CAUTION
Installation of adequate overpressure pro tec tion is recom-
mended to pro tect the reg u la tor from overpressure and
all down stream equip ment from damage in the event of
regulator failure.