Emerson Anderson Greenwood 81 Series - 3.4 Soft goods repair kit; Set pressure range; SET PRESSURE RANGE; Valve operating characteristic Tolerance

3
ANDERSON GREENWOOD SERIES 81 SPRING OPERATED PRESSURE RELIEF VALVES
INSTALLATION AND MAINTENANCE INSTRUCTIONS
4 VALVE ADJUSTMENT
4.1 General
Two adjustments are provided on gas service
valves, one for adjusting the opening pressure
and one for adjusting the closing pressure.
4.2 Set pressure
Turn spring adjustment screw on bonnet in most
of the way. Increase pressure to desired level
and back out screw until valve pops. Lock screw
with jam nut and retest. Readjust as required.
4.3 Reseat pressure
To adjust blowdown, turn blowdown adjustment
screw IN to shorten blowdown; OUT to increase
blowdown.
Note: if volume of test set up is too small,
blowdown will be set too short even though
pressure gauge indicates it to be correct.
Referto Section 4.5.
4.4 Adjustments tolerances
Two adjustments are provided on gas service
valves, one for adjusting the opening pressure
and one for adjusting the closing pressure.
SET PRESSURE RANGE
psig kpag Valve operating characteristic Tolerance*
Above 70 Above 483 Set pressure ±3%
70 and below 483 and below Set pressure ±2 psi (±13.8 kpa)
100 and above 689 and above Cracking pressure 95%
50 to 99 345 to 683 Cracking pressure 90 %
Below 50 Below 345 Cracking pressure 85%
100 and above 689 and above Reseat pressure 93%
50 to 99 345 to 683 Reseat pressure 90%
Below 50 Below 345 Reseat pressure 80%
* Percent tolerance is of specified set pressure
3.4 Soft goods repair kit
The part numbers for soft goods repair kits are listed below. Each kit contains the seat and seals
for all pressure ranges indicated.
Orifice TFE/KEL-F
Set pressure range
Vespel
Set pressure range
psig kpag psig kpag
4.5 Adjusting equipment
Where practical, valves should be set using
an accumulator large enough to accurately
read and set blowdown. For a -4 orifice up
to 4000psig (27579 kpag), -6 orifice up to
1410psig (9722 kpag) and a -8 orifice up to
600psig (4137kpag), a four cubic foot (0.113m
3
)
accumulator is recommended. Thesupply pipe
to the valve should be the same size as the inlet
or larger and not more than 10” (254 mm) long.
For all other valves, or if an accumulator is
not available for the sizes listed above, the
blowdown may be set using the following
method.
Turn the blowdown adjusting bolt all the way in
until it just touches the guide, then turn it out
the number of turns listed in the table.
F 04.4805.007 20-750 138-5171 04.4805.008 ≥ 751 ≥ 5178
G 04.4805.009 20-750 138-5171 04.4805.010 ≥ 751 ≥ 5178
H 04.4805.011 20-750 138-5171 04.4805.012 ≥ 751 ≥ 5178
J 04.4805.013 20-750 138-5171 04.4805.014 ≥ 751 ≥ 5178