Data Sheet

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Bulletin 71.1:912N

April 2010

D100124X012







The 912N Series direct-operated, spring-loaded regulators

are used in a variety of service and industrial applications.

These regulators have limited-capacity internal relief across

the diaphragm (see Figure 2) to help minimize overpressure.

Any outlet pressure above the start-to-discharge point of

the non-adjustable relief valve spring moves the diaphragm

off the relief valve seat, allowing excess pressure to bleed

out through the screened spring case vent. Inlet pressure

capabilities are the same for all regulators described in this

bulletin. However, outlet pressure ranges vary according to

construction (see Table 1).



  Disk/lever assembly

is attached to a roller-style pivot for smoother action.

Handwheel construction is available for adjustment of

the pressure setting.

  These regulators are suitable for a

variety of gaseous uids, including natural gas,

propane, and air. They are often used to supply

loading pressure to other units.

  “Drip lip” vent

helps resist blockage during icing conditions. When

the regulator is installed with the vent pointing down,

any ice that builds up forms a protective sheath

that helps keep the opening unobstructed. The vent

screen helps prevent foreign material from entering

the spring case and clogging or otherwise hindering

regulator operation.

  Diaphragm and disk/lever

assembly can be replaced without removing the

regulator from the pipeline.



Refer to Figure 2. When downstream demand decreases,

the pressure under the diaphragm increases. This pressure

overcomes the regulator setting (which is set by a spring).

Through the action of the pusher post assembly, the valve

disk moves closer to the orice and reduces gas ow. If

demand downstream increases, pressure under the diaphragm

decreases. Spring force pushes the pusher post assembly

P1024

Figure 1. 912N Series Regulator

Figure 2. 912N Series Operational Schematic

(Standard Spring Case Vent Shown)

INLET PRESSURE

OUTLET PRESSURE

ATMOSPHERIC PRESSURE































M1021

INLET PRESSURE

OUTLET PRESSURE

ATMOSPHERIC PRESSURE







Summary of content (4 pages)

PAGE 1
Bulletin 71.1:912N April 2010 912N Series Pressure Regulators Introduction The 912N Series direct-operated, spring-loaded regulators are used in a variety of service and industrial applications. These regulators have limited-capacity internal relief across the diaphragm (see Figure 2) to help minimize overpressure.
PAGE 2
Bulletin 71.1:912N Specifications Available Constructions See Table 1 Pressure Registration Internal Body Sizes and End Connection Styles Inlet: 1/4 NPT Outlet: 1/4 or 3/8 NPT Maximum Allowable Inlet Pressure(1) 250 psig (17,2 bar) Spring Case Vent Standard Construction: 1/8 NPT tapped with removable screen Standard Location Constructions Without Handwheel: Over body outlet Handwheel Constructions: Over body inlet Outlet Pressure Ranges(1) See Table 1 Approximate Weight 1.
PAGE 3
Bulletin 71.1:912N Table 1. Outlet Pressure Range Data available CONSTRUCTION 3 to 7-inches w.c. 5 to 10-inches w.c. 9.25 to 13-inches w.c. 912N Series without handwheel 12 to 24-inches w.c. 0.5 to 2.7 psig 2.7 to 5 psig 8 to 24-inches w.c. 912N Series with handwheel 2.7 to 5 psig control spring selection approximate point above outlet pressure setting at which internal relief starts to discharge outlet pressure range (7 to 17 mbar) 5 to 21-inches w.c. (12 to 25 mbar) 8 to 30-inches w.c.
PAGE 4
Bulletin 71.1:912N be protected from corrosive chemicals, debris, weather, condensation, or anything else that might clog or enter the spring case. 3.2 (81) 0.2 (5) Regulator dimensions are shown in Figure 3. Capacity Information 2.8 (71) Natural gas regulating capacities at selected inlet pressures and outlet pressure settings are given in Tables 2 and 3. Flows are in SCFH (60°F and 14.7 psia) of 0.6 specific gravity natural gas.