Masoneilan 87/88 Handwheel and Limit Stop Options for Spring-Diaphragm Actuators
Overview
The Masoneilan 87/88 handwheel and limit stop options add manual positioning and mechanical travel limits to the Baker Hughes Type 87/88 spring-diaphragm actuator. The technical specification lists the handwheel as optional for sizes 6, 10, 16, 23 and 23L, with 5, 9, 17, 25 and 440 turns for full travel, and shows adjustable up and down limit stops for each size on both Model 87 (air to close) and Model 88 (air to open). Both are specified when the actuator is ordered.
In Oman and the GCC, Seven Star LLC supplies the Masoneilan 87/88 handwheel and limit stops in Oman and the GCC. A handwheel lets operators stroke a control valve during a pneumatic failure or commissioning, while a limit stop caps stroke to protect trim or restrict flow, so both options appear often on RFQs from refineries, power plants and desalination stations.
Masoneilan 87/88 Handwheel Turns, Travel and Weight by Size
| Actuator size | Maximum travel | Turns for full travel | Weight without handwheel | Weight with handwheel |
|---|---|---|---|---|
| 6 | 0.8 in. (20 mm) | 5 | 44 lb (20 kg) | 59.5 lb (27 kg) |
| 10 | 1.5 in. (38 mm) | 9 | 86 lb (39 kg) | 105.8 lb (48 kg) |
| 16 | 2.5 in. (63 mm) | 17 | 209 lb (95 kg) | 244.7 lb (111 kg) |
| 23 | 2.5 in. (63 mm) | 25 | 264.5 lb (120 kg) | 319.6 lb (145 kg) |
| 23L | 4.0 in. (102 mm) | 440 | 374.8 to 507 lb | 416.6 to 612.9 lb |
The handwheel adds 15.5 lb (7 kg) on size 6, 19.8 lb (9 kg) on size 10, 35.7 lb (16 kg) on size 16 and 55.1 lb (25 kg) on size 23. Handwheel operation is limited to a maximum equivalent air supply of 60 psi (4.1 bar).
Neutral Position of the Masoneilan 87/88 Handwheel
Section 3 of the manual states that for full automatic operation the Masoneilan 87/88 handwheel must be in the neutral position, and that travel is limited if it is not. On a Model 87 the handwheel assembly can hold spring tension in the actuator when the diaphragm case is removed, so before the diaphragm is changed the lever pin and snap rings (size 3) or two cap screws and washers with the pivot pins (other sizes) must be removed and the assembly swung clear. Pivot pins are tightened afterwards to 60 ft-lb (81 N-m) on sizes 6 and 10 and 80 ft-lb (108 N-m) on sizes 16 and 23.
Masoneilan 87/88 Handwheel Bearing Maintenance
The handwheel bearing (item 34) is the main wear item. On sizes 6 and 10 (manual section 7.4) the technician frees the handwheel, removes the cap screw (20), washer (42), handwheel (41) and lock nut (43), releases the cover (57), pivot pins (33), snap rings (46) and lever pin (45), then turns the stem (39) clear of the traveling nut (40) and removes snap ring (35) to release bearing (34). The bearing is cleaned or replaced and packed, not merely coated, with Mobilux No. 2 grease or equal. On sizes 16 and 23 (section 7.5) the stem is freed through cap screw (97) and end flange (96). Torque is 300 ft-lb (407 N-m) for the stem cap screw (97) on sizes 16 and 23, and for the handwheel cap screw (20) 25 ft-lb (34 N-m) on sizes 6 and 10 and 66 ft-lb (90 N-m) on sizes 16 and 23.
Masoneilan 87/88 Handwheel Parts in the Parts Reference
The materials table lists the handwheel (item 41) in cast iron, the traveling nut (40) in leaded steel, the handwheel stem (39), pivot (36), bearing ring (37), lever (44), lever pin (45) and cover (57) in zinc-plated or plain carbon steel, the thrust bearing (34) in carbon steel, the lock pin (91) in stainless steel and the information plate (92) in vinyl. A “Steel Yoke and Aluminum Handwheel” option changes yoke (31 and 31a) and handwheel (41) materials. Retaining rings (35, 38 and 46) are easy to lose in the field, so keep a few in stock.
Limit Stops Beside the Masoneilan 87/88 Handwheel: Up Stop and Down Stop Heights
The adjustable limit stops fitted with the Masoneilan 87/88 handwheel add height, and the technical specification gives overall height B with a stop fitted. For Model 87 the up-stop heights are 19.5 in. (494 mm) on size 6, 25.4 in. (646 mm) on size 10, 36.4 in. (925 mm) on size 16 and 38.8 in. (987 mm) on size 23, and the down-stop heights are 19.8, 26.0, 37.2 and 39.9 in. For Model 88 the up-stop heights are 19.2, 25.1 and 35.5 in. on sizes 6, 10 and 16 and 982 mm on size 23, and the down-stop heights are 19.7, 25.9, 37.5 and 40.3 in. For the 23L with 3-15 or 6-30 psi springs and no handwheel the stops give 38.4 in. (975 mm) up and 39.9 in. (1,013 mm) down. The stop hardware comprises stem extension (81), lock nut (82), limit stop (83) in stainless steel, PTFE-lined bushing (84), stoppers (86 and 87) and O-ring (85).
Key Features
- Masoneilan 87/88 handwheel for sizes 6, 10, 16, 23 and 23L with 5 to 440 turns
- Adjustable up and down limit stops for Model 87 and Model 88
- Cast iron handwheel with a bearing packed in Mobilux No. 2 grease
- Neutral position for full automatic operation
- Maximum equivalent supply of 60 psi (4.1 bar)
Industrial Applications
Handwheels and limit stops appear on control valves in refineries, power plants, gas processing and desalination stations, where the Masoneilan 87/88 handwheel supports commissioning and air-failure operation and a stop protects trim or restricts flow. The base actuators are described on the Type 87/88 actuator page. Soft goods are covered by the size 16 spare parts kit.
Related: Masoneilan 87/88 Size 23L actuator and Masoneilan 87/88 standard temperature kits.
Related published Masoneilan pages: Masoneilan 010867003-779-0000 size 23 diaphragm.
Technical Specifications
The table lists the data Baker Hughes publishes for the Masoneilan 87/88 handwheel and limit stop options.
| Parameter | Specification |
|---|---|
| Model | Masoneilan 87/88 handwheel and adjustable limit stops (optional) |
| Manufacturer | Masoneilan (Baker Hughes) |
| Handwheel turns for full travel | Size 6: 5; size 10: 9; size 16: 17; size 23: 25; size 23L: 440 |
| Handwheel material | Cast iron handwheel (item 41); aluminum handwheel in the steel yoke option |
| Bearing grease | Mobilux No. 2 or equal |
| Limit stops | Up stop and down stop for Model 87 and Model 88, sizes 6 to 23L |
| Maximum supply pressure | 60 psi (4.1 bar) |
| Source documents | 87/88 Technical Specifications Rev. D (01/2026); 87/88 Instruction Manual Rev. G |
Request a Quote for Masoneilan 87/88 handwheel
Send Seven Star LLC an RFQ for Masoneilan 87/88 handwheel or limit stop parts with the actuator model, size, serial number and fitted options. In Oman and the GCC, we match the parts to the Baker Hughes documents on this page, confirm availability and arrange delivery from Muscat.
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For spare parts the serial number is decisive, since the factory record behind it lists trim, materials and actuator. Send a clear nameplate photo with serial number, model number, size and pressure class. For a new valve add the process data: fluid, inlet and outlet pressure, temperature, minimum, normal and maximum flow, required leakage class, fail position, air supply and control signal.Browse Masoneilan products by category: Control Valves, Valve Actuator, Regulators, Valve Positioner, Level Transmitter.
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