This document describes the Leslie Controls, Inc. Diaphragm Actuator models 35(R), 55(R), 85(R), and 135(R), providing installation, operation, and maintenance instructions.

Function Description

The Leslie Diaphragm Actuator is a device designed to control the movement of equipment, typically valves, by converting air pressure into mechanical force. It comes in two primary configurations:

Direct Actuator (Spring to Retract): In this configuration, the actuator stem retracts when air pressure is applied to the top of the diaphragm. When air pressure is removed, the spring extends the stem.
Reverse Actuator (Spring to Extend): In this configuration, the actuator stem extends when air pressure is applied to the bottom of the diaphragm. When air pressure is removed, the spring retracts the stem.

The actuator can be equipped with a Hand Operating Device (HOD) for manual control, allowing for manual adjustment of the stem position.

Important Technical Specifications

The actuators are available in various sizes, each with specific stroke lengths, diaphragm areas, and spring adjustor rod diameters.

Actuator Load Parameters (Table 1):

Actuator Size 35: Stroke 3/4 in, Area 34 in² (Direct) / 31 in² (Reverse), Spring Adjustor Rod Dia. 3/4 in.
Actuator Size 55: Stroke 1 in, Area 57 in² (Direct) / 54 in² (Reverse), Spring Adjustor Rod Dia. 7/8 in.
Actuator Size 85: Stroke 2 in, Area 90 in² (Direct) / 87 in² (Reverse), Spring Adjustor Rod Dia. 0.745 in.
Actuator Size 135: Stroke 3 in, Area 135 in² (Direct) / 131 in² (Reverse), Spring Adjustor Rod Dia. 0.995 in.

Torque Values (ft-lbs) (Table 2 - Direct Actuator):

Lower Dia. Casing Bolts (26):
- Size 35: 15-20
- Size 55, 85: 30-36
- Size 135: 45-50
Upper Dia. Casing Bolts (22,23):
- Size 35, 55, 85, 135: 15-20

Torque Values (ft-lbs) (Table 3 - Hand Operating Device - Direct Actuator):

Size 35: 15-20 (Item 1), 2-5 (Item 5), 50-80 (Item 17)
Size 55, 85: 15-20 (Item 1), 2-5 (Item 5), 50-80 (Item 17)
Size 135: 30-36 (Item 1), 2-5 (Item 5), 50-80 (Item 17)

Torque Values (ft-lbs) (Table 4 - Reverse Actuator):

Lower Dia. Casing Bolts (23,24):
- Size 35R: 15-20
- Size 55R/55AR, 85R/85AR: 30-36
- Size 135R: 45-50
Upper Dia. Casing Bolts (18,19):
- All Sizes: 15-20

Torque Values (ft-lbs) (Table 5 - Hand Operating Device - Reverse Actuator):

Size 35R: 15-20 (Item 1), 3-5 (Item 6)
Size 55R/55AR, 85R/85AR: 15-20 (Item 1), 15-20 (Item 6)
Size 135R: 30-36 (Item 1), 15-20 (Item 6)

Dimensional Information (Tables 4 & 5): Detailed dimensions (J, J-J, L, M, N-1, N-2, N-3, P, R, S, T, U, V, W, X, Z) are provided for both direct and reverse acting actuators across all sizes, in both inches and millimeters. These tables also include net weights for cast aluminum and cast iron versions, with and without the Hand Operating Device.

Usage Features

Vertical Mounting: Actuators are designed for vertical mounting. Consult the factory for non-vertical installations, as piping supports may be required.
Air Supply: Instrument air should be used to operate the actuator, with a maximum supply pressure of 60 psig.
Stroke Adjustment: The actuator stroke can be adjusted by retracting the stem (removing air for direct, applying air for reverse) and screwing the equipment stem further into the actuator.
Spring Load Setting: The spring load is adjusted by turning the spring adjusting nut (35 or 40) after removing all air pressure. The force output can be measured by slowly applying air and recording the pressure at which the actuator begins to move, then multiplying by the diaphragm area.
Hand Operating Device (HOD): The HOD allows for manual positioning of the actuator stem. It includes a handwheel, handscrew, and packing gland.

Maintenance Features

Disassembly and Reassembly: Detailed step-by-step instructions are provided for disassembling and reassembling both direct and reverse acting actuators, as well as their Hand Operating Devices.
Safety Precautions: Emphasizes the importance of completely removing spring load before disassembly to prevent injury or death. Also warns against turning the valve shaft if the actuator is mounted to a valve, unless the valve plug is lifted off the valve seat.
Component Inspection: Before reassembly, all components must be free from nicks, burrs, or defects.
Torque Specifications: Specific torque values are provided for various bolts and nuts during reassembly to ensure proper sealing and structural integrity.
Stem Seal Pre-setting: Instructions are given for pre-setting the stem seal in reverse acting actuators to ensure proper sealing and prevent failure.
Troubleshooting Guide: A table outlines common problems, possible causes, and recommended solutions:
- Equipment not shutting off or insufficient force: Possible causes include insufficient spring load or blockage in equipment.
- Actuator not fully stroking or giving enough load: Possible causes include incorrect air supply pressure, seal leakage, or a broken spring.
- Actuator not returning to open/closed position: Possible causes include blockage in equipment or a broken spring.
- Actuator not fully stroking with control signal: Possible cause is incorrect bench range.
- Actuator not moving smoothly: Possible causes include over-tightened valve packing or spring rubbing on the spring case.
Spare Parts List: Comprehensive lists of parts for both direct and reverse acting actuators, including material, quantity per unit, and reference numbers for each size. This facilitates ordering and replacement of components.

Leslie 35 - Page 13

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