SELECTING
PRESSURE PILOTS
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SELECTING PRESSURE PILOTS
Any of the Main Valves described in the Main Valve Section can
be combined with any of the Pilots listed below to produce the
SPENCE Pressure Regulator. This Regulator will reduce and
regulate a steady or varying initial pressure, within the range
specified, so as to maintain a constant, adjustable,
predetermined delivery pressure. The table below lists the
principal Pressure Pilots.
D SERIES PILOTS meet the requirements of the majority of all
pressure regulator problems. They are spring-loaded. Other
Pilots are modifications of the D Series for specific purposes.
A SERIES PILOTS are air-loaded. These Pilots are recommended where frequent changes in setting must be made and
the Regulator is not easily accessible.
In any one Series of Pilots a larger Diaphragm will produce closer
accuracy of control but with less range in delivery pressure.
Water Service Pilot operated Regulators are not uniformly
satisfactory as water reducing valves unless the delivery
system has the ample cushioning afforded by an elevated tank
or air chamber. When the flow is intermittent to an inflexible
system, the SPENCE Type D34 Direct Operated Pressure
Reducing Valve is recommended.
Type Service Conditions Diaphragm Loading Main Valve
Cast Iron Cast Bronze Cast Steel
Delivery Pressure
Maximum Maximum Maximum Maximum Maximum Maximum Normal
Initial Temper- Initial Temper- Initial Temper- Accuracy
Pressure ature Pressure ature Pressure ature Minimum Maximum Diameter Material
psi °F psi °F psi °F psi psi ± inches
D 250 450 — — 600 750 3 150 1 psi 31/2 St. Stl. Spring E or C Series
D2 250 450 — — 600 750 100 300 2 psi 31/2 St. Stl. Spring E or C Series
D5250450————1 251/2 psi 53/4 St. Stl. Spring E or C Series
D120 250 450 — — 600 750 5 150 1 psi 41/2 St. Stl. Spring E or C Series
A73 250 450 — — 600 750
1
/
2 psi 3
1
/
2-7
1
/
4
b
St. Stl. Air E or C Series
A53 250 450 — — 600 750
1
/2 psi 31/2-53/4bSt. Stl. Air E or C Series
A 250 450 — — 600 750
1
/2 psi 31/2 St. Stl. Air E or C Series
A35250450————
1
/
8 psi 5
3
/
4-3
1
/
2
b
St. Stl. Air E or C Series
A54 250 450 — — 600 750 1 psi 41/2-53/4bSt. Stl. Air E or C Series
A70 250 450 — — 600 750 2 psi 71/
4 St. Stl. Air E or C Series
A86 250 450 — — 600 750
1
/
2 psi 4
1
/
2 St. Stl. Air E or C Series
A87 250 450 — — 600 750
1
/2 psi 71/4 St. Stl. Air E or C Series
A85 250 450 — — 600 750
1
/
2 psi 3
1
/
2-5
3
/
4
b
St. Stl. Air E or C Series
A84 250 450 — — 600 750
1
/2 psi 31/2 St. Stl. Air E or C Series
A83 250 450 — — 600 750
1
/2 psi 31/2 St. Stl. Air E or C Series
A82250450————
1
/
8 psi 5
3
/
4 St. Stl. Air E or C Series
Safety
Pilot
— — 300 500 600 750 5 175 — 31/
2 St. Stl. Spring E or C Series
P125 250 450 — — 600 750 5 175 1 psi 4
1
/2 St. Stl. Spring E or C Series
b
These Pilots have dual diaphragms, the first size being the control diaphragm and the second, the air loading diaphragm.
See response
curves on
A Pilot
Product Page
50
PRESSURE REGULATOR PILOTS
NOTES ON SELECTION OF PILOTS
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