MSS SP 128 | Ductile Iron Gate Valves

Technical Drawings, Design Features & Materials

Design features of MSS SP 128 ductile iron gate valves: RF flanged end connection; solid wedge (one-piece); OS&Y rising stem or non-rising stem; bolted bonnet; handwheel operated; metal seated (copper alloy seating surfaces); Class 125 and Class 250 gate valve bodies and bonnets shall be either ASTM A536 or ASTM A395 ductile iron and shall have minimum wall thickness as specified in ASME B16.1 for the corresponding Class and NPS fitting; Class 150 and Class 300 gate valve bodies and bonnets shall be ASTM A395 ductile iron and shall have the minimum wall thickness as specified in ASME B16.42 for the corresponding Class and NPS fitting. Sizes available: 2″~24″ for Class 125; 2″~12″ for Class 150, Class 250, and Class 300. Face-to-face dimensions shall be in accordance with ASME B16.10.

Valve Part	Materials
Body	ASTM A536 ASTM A395
Bonnet	ASTM A536 ASTM A395
Disc	ASTM A536 ASTM A395
Seat Ring on Wedge	ASTM B62 C83600
Seat Ring on Body	ASTM B62 C83600
Stem	ASTM B16 C36000 AISI 420
Packing	Graphite
Handwheel	ASTM A536 ASTM A395

*ASTM A536: standard specification for ductile iron castings; Grade 60-40-18 and Grade 65-45-12 are generally used.
*ASTM A395: standard specification for ferritic ductile iron pressure-containing castings for use at elevated temperatures; Grade 60-40-18 and Grade 65-45-15 are generally used.

Dimensions

NPS	L mm	H mm	D mm
2"	178	375	178
2-1/2"	190	422	178
3"	203	475	200
4"	229	606	254
5"	254	683	300
6"	267	828	300
8"	292	1003	348
10"	330	1211	400
12"	356	1421	457
14"	381	1641	560
16"	406	1828	560
18"	432	2047	610
20"	457	2246	610
24"	508	2632	765

*For Class 125, metal seated, OS&Y rising stem ductile iron gate valves, 2″~24″.

NPS	L mm	H mm	D mm
2"	216	384	175
2-1/2"	241	436	200
3"	283	492	254
4"	305	610	300
5"	381	715	300
6"	403	812	348
8"	419	1024	400
10"	457	1211	457
12"	502	1386	457

*For Class 250, metal seated, OS&Y rising stem ductile iron gate valves, 2″~12″.

NPS	L mm	H mm	D mm
2"	178	302	178
2-1/2"	190	332	178
3"	203	335	200
4"	229	423	254
5"	254	485	300
6"	267	545	300
8"	292	644	348
10"	330	769	400
12"	356	860	457
14"	381	987	560
16"	406	1044	560
18"	432	1148	610
20"	457	1257	610
24"	508	1418	765

For Class 125, metal seated, non-rising stem (NRS) ductile iron gate valves, 2″~24″.

NPS	L mm	H mm	D mm
2"	216	343	175
2-1/2"	241	381	200
3"	283	419	254
4"	305	470	300
5"	381	527	300
6"	403	610	348
8"	419	724	400
10"	457	864	457
12"	502	914	457

For Class 250, metal seated, non-rising stem (NRS) ductile iron gate valves, 2″~24″.

Dimensions for Class 150 and Class 300 are available upon request.

Tests

Shell test, hydrostatic seat test, and gas seat test shall be made on all completed ductile iron gate valves. The valves in the partially open position with both ends sealed shall be subjected to hydrostatic or gas-test pressure of at least 1.5 times the cold working pressure. The hydrostatic-seat test pressure shall be not less than the rated working pressure, which shall be applied successively on each side of the closed gates, and the opposite side shall be checked for leakage. The accepting criteria of the test results as well as the minimum duration of tests are the same as that of the gray iron gate valves.