Groth 3000 Series - Manual (Page 21)

ADDENDUM A
Groth Corporation continually reviews and revises designs and specifications to improve quality and performance of its
manufactured products. The specifications and procedures in this addendum supersede the applicable sections of the
manual for all Groth blanket gas regulators manufactured after
7/1/1994.
PRESSURE SETTING
All springs and spring ranges are the same, however, balance
springs have been added in some spring ranges. Refer to tables 3, 4
and 5 below.
FLOW CAPACITY SETTING
The setting procedure is the same, but additional flow restrictions
are available, down to 5% of full flow. Refer to table 6 below.
DISASSEMBLY
Some regulators utilize a balance spring inside the body (refer to
Tables 3 & 4 and Figure 12 on the reverse side of this page).
Hex bolts [28] are used in place of the countersunk screws [30] to
mount the body to the actuator housing. As the bolts are removed,
the internal spring [30] will force the guide ring [23] out of the
body. The force is not great enough to present a hazard, but caution
should be used to prevent damage to the ring. The spring can then
be removed as part of the piston sub-assembly. Proceed with
disassembly according to the manual.
ASSEMBLY
Prepare the body, piston sub-assembly and upper actuator housing
according to the manual. Attach the piston diaphragm [21],
diaphragm retainer [9] and lower piston pin [26] to the piston sub-
assembly. Note: The reinforced (rough) surface of the piston
diaphragm [21] must be facing away from the piston, ie: high
pressure on the smooth side. This is critical for the top (inlet)
piston diaphragm. Proceed with assembly according to the
manual, except where a balance spring is utilized, then proceed as
follows:
Slide the small end of the balance spring [30] over the piston sub-
assembly until it seats on the retaining ring [32]. Insert this
piston/spring sub-assembly into the body. Fit the large end of the
balance spring into the groove in the guide ring [23] and compress
the spring as you insert the guide ring and O-Ring [22] into the
body. Hold the guide ring as you position the actuator housing [12]
onto the body. The weight of the housing will maintain
compression of the spring. Install hex bolts [28] and lockwashers
[29] and tighten uniformly. Proceed with assembly according to the
manual.
See piston/body/diaphragm sub-assembly drawing (Figure 12) and
bill of materials on the next page.
TABLE 3
Spring Table
Model 3000
Set Pressure Range: 2" WC to 2.0 PSI
Tank MAWP: 25 PSI
Spring
Range
Min.
Setting
Max.
Setting
Spring
P/N
Balance
Spr P/N
1 2.0
In WC
3.4
InWC
84209001
Yellow
85493001
Yellow
2 3.5
In WC
6.3
InWC
84209002
Green
Not
Required
3 6.4
In WC
10.9
InWC
84209003
Pink
Not
Required
4 11.0
In WC
18.5
InWC
84209004
Blue
Not
Required
5 18.6
In WC
27.6
InWC
84209005
White
Not
Required
6 1.0
PSI
1.37
PSI
84209006
Gray
Not
Required
7 1.38
PSI
2.0
PSI
84209007
Black
Not
Required
TABLE 4
Spring Table
Model 3010
Set Pressure Range: 0.5" WC to 2.0" WC
Tank MAWP: 10 In WC
Spring
Range
Min.
Setting
Max.
Setting
Spring
P/N
Balance
Spr P/N
8 0.5
In WC
0.6
In WC
84209008
Red
85493001
Yellow
1 0.7
In WC
1.0
In WC
84209001
Yellow
85493001
Yellow
2 1.1
In WC
2.0
In WC
84209002
Green
Not
Required
TABLE 5
Spring Table
Model 3020
Set Pressure Range: 2.0 PSI to 10.0 PSI
Tank MAWP: 25 PSI Standard 150 PSI Optional
Spring
Range
Min.
Setting
Max.
Setting
Spring
P/N
Balance
Spr P/N
4 2.0 PSI 3.3 PSI
84209004
Blue
Not
Required
5 3.4 PSI 5.1 PSI
84209005
White
Not
Required
6 5.2 PSI 7.3 PSI
84209006
Gray
Not
Required
7 7.4 PSI 10.0 PSI
84209002
Green
Not
Required