Mark 70 Series Sliding Gate Control Valve

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Enclosed multi-spring actuator minimises the dead band
Flow through gate seats for quieter operation
Short stroke offering faster and more accurate regulation

The Mark 70 series combines multiple spring actuators, and the sliding gate designs for a pneumatically operated diaphragm control valve. The springs are completely enclosed minimizing the dead band and making the valve field reversible without special tools or extra parts.

By utilising a sliding gate seat design, it allows for a quieter operation as well as a longer lasting gate seat as there is less turbulence inside the valve as it provides a straight through flow. It also means the gate has a shorter stroke allowing for faster responses.

Body and trim materials

The body of the Mark 70 can be manufactured from cast iron, ductile iron, bronze (DN15-50), carbon steel and stainless steel. 316 stainless steel is used for the trim when the body is made from stainless steel and 303 SS is used for all other body materials.

Diaphragm materials

The diaphragm is Buna-N which can operate in temperature up to 93°C. It has Cv rating up to 30 and pipe sizes of between ¼" and 2". Leakage protection is maximised with the stem packing being four times greater than the stem travel.

Key specifications

Sizes	(note: 1/4" & 3/8" sizes use 1/2" body with reducers) Mark 70/70PG: 1/4" through 2" (DN8 through DN50) Mark 707: 1/2" through 6" (DN8 through DN150) Mark 711: 2-1/2" through 6" (DN65 through DN150)
End connections	Threaded (NPT, BSPT, BSPP – through 2" sizes/DN50) ANSI Flanges (150#, 300#) DIN Flanges (PN10/16, PN25/40)
Body materials	Cast Iron Ductile Iron Bronze (1/2" – 2"/DN15 - DN50) Carbon Steel (WCB) Stainless Steel (CF8M)
Trim materials	303SS for CI and DI body valves 316SS for SS body valves
Seat materials	Jorcote on SST – standard
Yoke materials	Cast Iron
Actuator	Steel
Diaphragm	Buna-N (standard to 200°F/93°C)
Stem packing	spring-loaded Teflon (to 450°F/232°C); Graphite (to 1200°F/649°C)
Service	steam, water, gas, oil, air and chemicals
Shutoff	ANSI Class IV