Unions

2.10.3.4

Unions

a.

Unions For Steel Pipe: ASME B16.11, ASME B16.39threaded.

Unions

for zinc coated pipe shall be zinc coated.

b.

Unions For Copper Tubing: ASME B16.22.

For instrument air,

unions may be compression joint type.

2.10.4

Flanges

ASME B16.5, forged steel, welding type. Remove the raised faces on flanges

when used with flanges having a flat face. Except as specified otherwise,

pressure and temperature limitations shall be as specified in ASME B16.5

for the proper class and service, and the type face specified.

2.10.5

Valves

2.10.5.1

Low Pressure

Valves for maximum working pressure of 1034 kPa (gage) 150 psig saturated

steam or 1550 kPa (gage) 225 psig W.O.G. (Water, Oil, Gas) at 93 degrees C

200 degrees F, non-shock service. For working pressures not exceeding 862

kPa (gage) 125 psig saturated steam or 1379 kPa (gage) 200 psig water at 93

degrees C 200 degrees F non-shock service, Class 125 may be used in lieu of

Class 150 or Class 250.

a.

Valve Sizes 50 mm 2 Inches and Smaller:

(1) Non-Throttling Valves: Gate valves, bronze, wedge disc,

rising stem, Class 150, MSS SP-80 or ball valves, bronze, double

stem seals, stainless steel ball and shaft, tight shutoff.

(2)

Globe Valves and Angle Valves:

Bronze, Class 150, MSS SP-80.

(3) Check Valves: Bronze, Type [IV, swing check] [III, lift

check], Class 150, MSS SP-80.

b.

Valve sizes 65 mm 2 1/2 inches and larger.

(1) Gate Valves: Flanged, cast iron, Class 250, MSS SP-70 or

steel, Class 150, ASME B16.34. Valves shall have wedge disc,

outside screw and yoke (OS&Y), rising stem; valves 200 mm 8 inches

and larger shall have globe valved bypass.

(2) Globe Valves and Angle Valves: Flanged, cast iron, Class

250, MSS SP-85 or steel, Class 150, ASME B16.34.

(3) Check Valves: Flanged, cast iron, Class 250 or steel, Class

150, Type [_____], [lift] [swing] check, style [_____], ASME B16.34.

2.10.5.2

Medium Pressure

Valves for maximum working pressure of 1723 kPa (gage) 250 psigsteam at a

maximum temperature of 232 degrees C 450 degrees F or 3445 kPa (gage) 500

psig W.O.G. at 93 degrees C 200 degrees F (non-shock).

Valve sizes 65 mm 2 1/2 inches and larger:

a.

Gate Valves:

Flanged or butt welded, cast iron, Class 250, MSS

SECTION 15511N

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