II. INSTALLATION
IOM-6987
11-16
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 flow direction
match es the arrow cast on the body. The body
has an angle con fig 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 optional.
5. All installations should include an upstream relief
de vice if the inlet pressure could exceed the
pressure 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
recommended to pro tect the reg u la tor from overpressure
and all down stream equip ment from damage in the event
of regulator failure.
ISO Registered Company
