Masoneilan Model 52/53 Spring-Return Actuators, Sizes 12, 16 and 20

Overview

The Masoneilan Model 52/53 spring-return actuators are the fail-safe versions of the Baker Hughes 51/52/53 pneumatic cylinder actuator series. Model 52 is “air to extend” and Model 53 is “air to retract”; a mechanical spring drives the stem to a defined position when the air supply is lost, so the valve moves to a known safe state without a volume tank. The technical specification lists three sizes, 12, 16 and 20, with piston areas of 112, 180 and 287 sq. in., strokes up to 6 in. and a standard maximum supply of 150 psig (1.03 MPa).

In Oman and the GCC, Seven Star LLC supplies the Masoneilan Model 52/53 spring-return actuators to Oman and the GCC. They suit larger globe valves in steam and hydrocarbon service and on-off isolation duties at refineries, gas plants and power stations where a spring-diaphragm actuator cannot supply enough thrust.

What the Spring Does in the Masoneilan Model 52/53 Spring-Return Actuators

In Model 52 air enters the top plate and pushes the piston down; in Model 53 pressure enters through the yoke and moves the piston up. In both the spring returns the stem on loss of air. Which model is correct depends on whether the valve plug must open or close on air failure, which follows from the trim action and the process safety requirement.

Both models use a separate spring cartridge. The spring is pre-compressed inside it before fitting, which allows safe assembly and, as the specification states, makes the cartridge fully field reversible, reducing the spares a plant must hold.

Masoneilan Model 52/53 Spring-Return Actuators: Sizes, Strokes and Spring Ranges

In metric units the standard springs are 0.07 to 0.17, 0.14 to 0.28 and 0.17 to 0.34 MPa. Sizes 16 and 20 can be supplied with intermediate strokes between 0.25 in. and 6 in. on standard springs, which shifts the working range as the next section shows. Ambient range is −20°C to +83°C.

Optional Spring Ranges for the Masoneilan Model 52/53 Spring-Return Actuators

Changing the stroke on standard springs shifts the working pressure range. For a Model 52 size 12 at 3.75 in. the three springs become 10-24, 20-39 and 25-48 psi, and at 3 in. 10-21, 20-35 and 25-44 psi. For a Model 53 size 12 at 3.75 in. they become 11-25, 21-40 and 27-50 psi, and at 3 in. 14-25, 25-40 and 31-50 psi. A positioner calibrated for the standard range will therefore not match the actuator if the stroke was changed, so the order must state the exact valve stroke and available supply pressure.

Dimensions and Weights of the Masoneilan Model 52/53 Spring-Return Actuators

Dimension D is 14.69 in. (373 mm) for size 12, 18.15 in. (461 mm) for size 16 and 22.56 in. (573 mm) for size 20. Overall height F at nominal travel is 39.1 in. (994 mm) for size 12 at 4 in., 39.5, 44 and 50 in. for size 16 at 2.5, 4 and 6 in., and 41.1, 45.6 and 51.6 in. for size 20. Standard weights without handwheel are 412 lb (187 kg) for a Model 52 size 12 and 410 lb for a Model 53; size 16 Model 52 weighs 712, 761 and 864 lb; size 20 Model 52 weighs 1,157, 1,261 and 1,387 lb, with Model 53 slightly lighter. Plan lifting equipment and structural support from these figures.

Piping, Mounting and Stops for the Masoneilan Model 52/53 Spring-Return Actuators

On the Masoneilan Model 52/53 spring-return actuators the air connections are 3/4 in. NPT on the top plate and yoke, with 1 in. or three 3/4 in. ports as options on units without a volume chamber. Split clamps join valve stem and piston stem and provide anti-rotation. A single adjustable travel stop (up or down, never both) can be supplied: on size 12 at 4 in. the up stop adjusts valve opening from 50 to 100 percent and the down stop from 0 to 50 percent. On size 20 the stop is available only without the hydraulic handjack. Seven Star LLC checks these limits against your valve before quoting.

Key Features

• Masoneilan Model 52/53 spring-return actuators in sizes 12, 16 and 20
• Air to extend (Model 52) or air to retract (Model 53) with spring fail-safe
• Field-reversible pre-compressed spring cartridge
• Standard springs of 10-25, 20-40 and 25-50 psi and supply up to 150 psig
• Optional adjustable travel stop, handwheel or hydraulic handjack

Industrial Applications

Fail-safe cylinder actuators drive large control and shutdown valves in steam, hydrocarbon and utility service. In Oman the Masoneilan Model 52/53 spring-return actuators serve refineries, gas plants, power stations and desalination sites. Maintenance centres on the O-rings (item 21), guide ring (16) and, without a handwheel, the rod scraper (34). For the full family see the Type 51/52/53 piston actuator page; when less thrust is enough compare the Type 87/88 spring-diaphragm actuators.

Related Masoneilan items: Masoneilan 50 Series soft goods kits, Masoneilan 51/52/53 manual override and Masoneilan Model 51 double-acting actuator.

Related published Masoneilan pages: Masoneilan 10000 Series double-port valve.

Technical Specifications

The table lists the data Baker Hughes publishes for the Masoneilan Model 52/53 spring-return actuators.

Request a Quote for Masoneilan Model 52/53 spring-return actuators

Send Seven Star LLC an RFQ for the Masoneilan Model 52/53 spring-return actuators with the valve model and stem size, required stroke, supply pressure, fail-safe direction and any handwheel or stop options. In Oman and the GCC, we confirm the configuration against the Baker Hughes technical specification linked on this page and arrange delivery from Muscat.