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IB-53-B

 C-1801 Pneumatic Operators

Repair and Adjustment

This bulletin should be used by experienced personnel as a guide to the repair and adjustment of Armstrong
C-1801 Pneumatic Operators.  Selection or installation of equipment should always be accompanied by
competent technical assistance.  We encourage you to contact Armstrong or its local representative if
further information is required.

WARNING: Be sure that the steam supply to the device being controlled has been 

turned

off 

and that the body is 

at a safe handling temperature 

before attempting

inspection or repairs to the operator!

Maintenance procedures for the Armstrong pneumatic operator should include:

disassembling the operator;

installing the operator;

replacing stem seals;

changing operator springs;

replacing the diaphragm;

replacing the valve and seat.

Please refer to Figure 2-1 for part locations and identification.

A. REMOVING THE OPERATOR AND INSPECTING THE VALVE AND SEAT

The operator must be removed to inspect or replace valves and seats, or to recondition the
operator.
1. Turn off fluid supply to the device being controlled.
2. Turn off the instrument air to the operator.  Disconnect the control line.
3. Unscrew the operator to remove it.
4. Inspect the valve.  A properly wearing valve has a bright NARROW ring all the way

around its circumference.

5. Inspect the seat.  A properly wearing seat has a SHARP EDGE, with no nicks or gaps.
6. If the valve and seat are wearing properly, proceed to Section G, Steps 9, 10,  and 11.

Valves and seats must 

ALWAYS

 be replaced as a set.  Replacing the valve requires

disassembly of the operator.

Summary of Contents for C-1801

Page 1: ...r installing the operator replacing stem seals changing operator springs replacing the diaphragm replacing the valve and seat Please refer to Figure 2 1 for part locations and identification A REMOVING THE OPERATOR AND INSPECTING THE VALVE AND SEAT The operator must be removed to inspect or replace valves and seats or to recondition the operator 1 Turn off fluid supply to the device being controll...

Page 2: ...TOR Most subsequent repair procedures require disassembly of the operator 1 Turn the spring adjusting screw 3 clockwise until it moves freely 2 Remove the four flange screws 1 3 Remove the operator cover 2 4 Remove the spring adjusting screw 3 spring adjusting disc 6 snap ring 5 and fric tion washer 4 5 Remove the spring 7 C REPLACING THE VALVE AND SEAT ALWAYS replace the valve and seat as a set 1...

Page 3: ...lower quad ring 22 and the upper quad ring 21 Turn the operator back over so the valve points down 11 Replace the washer 17 the diaphragm 9 the piston 8 washer 16 and hex nut 15 Tighten the hex nut 15 12 Assemble the pneumatic operator in accordance with Section G E CHANGING THE OPERATOR SPRINGS 1 Remove and disassemble the operator in accordance with Sections A and B 2 Place new spring 7 in the b...

Page 4: ... specified with the start point set at 3 psi NOTE The operating range is not adjustable only the start point is adjustable If a different range is desired change the operator spring in accordance with Section E 1 Place a pencil pen or similar implement through the hole in the spring adjustment screw 3 2 Hook up the air line to the operator with the air line connected to a gauge and a regulator 3 S...

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