Type 167A
Fisher Controls
Instruction Manual Type 167A Three-W ay Switching Valve
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September
1980
Form 1932
INTRODUCTION Scope of Manual This instruction manual includes installation, adjustment, maintenance, and parts information for the Type 167A three-way switching valve (see figure 1).
Description The Type 167A is a compact, three-way switching valve usually installed to provide lock-up action should the system operation deviate from normal (see figure 2). This valve can be field or panel mounted. In the installation example shown in figure 3, the supply or control pressure is applied to the switching valve diaphragm through port D. As long as the supply pressure on the diaphragm overcomes the opposing spring, the switching valve plug will be in the up position allowing the positioner signal to flow from port A to port B and into the actuator diaphragm case. If the supply pressure decreases sufficiently, the switching valve plug will stroke down. Positioner pressure than flows from port A to port C. Since port C is plugged, the positioner pressure is isolated from the actuator. Port B is blocked with pressure locking the actuator upon loss of supply pressure.
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Figure 1. Type 167A Three-W ay Switching
The Type 167A is preadjusted at the factory according to the operating conditions specified on the order. However, should these conditions change, the switching valve can be easily readjusted by turning a single screw.
Specifications Specifications for the Type 167A valve are shown in table 1. eFisher Controls International, Inc. 1980; All Rights Reserved
AE5378-B A2425-1
Figure 2. Typical Switching
Valve Schematic
Valve
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Type 167A Table 1. Specifications MAXIMUM INLET PRESSURE
250 psig (17.2 bar) at ports A, B, and C
MA TERIAL TEMPERA TURE CAP ABILITIES
-20 to +150_ (-29 to +66_C)
SPRING RANGES
See table 2
CONTROL CONNECTIONS
1/4 in. NPT female
MAXIMUM CONTROL PRESSURE TO DIAPHRAGM
100 psig (6.9 bar) at port D
APPROXIMA TE WEIGHT
1 lb (0.5 kg)
INST ALLA TION W ARNING
Overpressuring a switching valve or associated equipment may cause leakage, part damage, or personal injury due to bursting of pressure-containing parts or explosion of accumulated gas. Do not install a switching valve where service conditions can exceed the specifications listed in table 1.
MAINTENANCE Parts are subject to normal wear and must be inspected and replaced periodically. The frequency of parts inspection and replacement depends upon the severity of service conditions. Instructions are given below for complete disassembly and assembly. Disassemble the valve only as far as needed to accomplish the required task. Then, begin the ‘‘Assembly’’ procedure at the appropriate step. Key numbers used in these procedures are shown in figure 4.
1. Install the switching valve so that the vent opening is facing downward. Protect the vent opening against the entrance of moisture or any other material that could plug the vent. 2. Apply pipe compound to male pipeline threads. Connect piping to the body connections. 3. Install the valve to achieve the desired switching results. Connect the control pressure line to the connection in the lower diaphragm casing (connection D, figure 3). A is the common inlet connection and B and C are outlet connections. All connections are 1/4-inch NPT. Flow is either A to B or A to C.
ADJUSTMENT Refer to the label, located on the spring case, for the spring range. To change the spring setting, loosen the locknut (key 11, figure 4), and rotate the adjusting screw (key 10, figure 4). Rotating the adjusting screw clockwise into the spring case (key 1, figure 4) increases the control pressure at which the valve switches. Rotating the adjusting screw counterclockwise decreases the switching pressure. Tighten the locknut after adjustment.
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W ARNING To avoid personal injury and equipment damage caused by sudden release of process pressure or explosion of accumulated gas, isolate the valve from all pressure and release all pressure from the valve body and diaphragm casing before attempting maintenance.
Disassembly 1. Loosen the hex nut (key 11). Rotate the adjusting screw (key 10) counterclockwise until all compression has been relieved from the spring (key 9). 2. Disconnect piping from the bottom connector (key 3). Unscrew and remove the bottom connector, valve plug (key 4), gasket (key 22), and spring (key 24). 3. Unscrew and remove the machine screws (key 12) from the spring case. Remove the spring case, upper spring seat, and spring (keys 2, 8, and 9). 4. Remove the diaphragm assembly (key 7). 5. Unscrew the stem guide assembly (key 15) and gasket (key 23).
Type 167A Table 2. Spring Selection SPRING SET POINT RANGE Standard
Panel Mounted
Psig
Bar
Psig
Bar
5-18 18-30 30-100
0.3-1.2 1.2-2.0 2.0-6.9
5-12 12-20 20-80
0.3-0.8 0.8-1.4 1.4-5.5
SPRING PART NUMBER
1B9860 27212 1B7883 27022 1K7485 27202
MAXIMUM PRESSURE CHANGE ON DIAPHRAGM
SPRING COLOR CODE
FOR FULL STROKE Psi
Green Cadmium Red
5 8 15
Bar (Differential)
0.3 0.6 1.0
2. Slide the valve plug (key 4) into the stem guide assembly (key 15) through port B. 3. Slide the gasket (key 22) onto the bottom connector (key 3), and screw the bottom connector with valve plug spring (key 24) and retaining ring (key 25) into the valve body (key 1). 4. Place the diaphragm assembly (key 7) on the valve plug (key 4) stem, and align the holes in the diaphragm and valve body.
Note
To ensure a good seal between the valve body (key 1) and spring case (key 2), there must be slack in the diaphragm when attaching the spring case to the valve body. Make certain the adjusting screw (key 10) is completely backed out. This is to prevent the spring (key 9) from exerting any pressure on the diaphragm during assembly of the spring case and valve body. 5. Install the spring (key 9), upper spring seat (key 8), and spring case (key 2). Secure the spring case to the valve body (key 1) using the machine screws (key 12). 6. Re-connect the piping to the bottom connector and to the control connection in the diaphragm casing. 7. Adjust the spring by following the ‘‘Adjustment’’ instructions. AV2202-B
Figure 3. Type 167A Switching Valve with Connection B, C, & D Labeled
A,
PARTS ORDERING Assembly 1. Slide the gasket (key 23) onto the stem guide assembly (key 15) and screw the stem guide assembly into the valve body (key 1).
When corresponding with the sales representative about this valve, mention all data stamped on the label. When ordering replacement parts, also state the complete 11-character part number of each part required as found in the following parts list.
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Type 167A
PARTS LIST
Key 10 10 11
Key 1 2
3 4
7*
8 9
Description
Description Adjusting Screw, Steel Handwheel, Steel zn pl Hex Nut, Steel
1B7986 28982 1B7992 000A2
Part Number
Valve Body, Aluminum Spring Case, Aluminum Standard Panel Mounted Bottom Connector, Aluminum Valve Plug Nitrile and Aluminum Viton and Aluminum Diaphragm Assembly Nitrile Viton Upper Spring Seat, Steel Spring, Steel Standard 5 to 18 psig (0.3 to 1.2 bar) 18 to 30 psig (1.2 to 2.0 bar) 30 to 100 psig (2.0 to 6.9 bar) Panel Mounted 5 to 12 psig (0.3 to 0.8 bar) 12 to 20 psig (0.8 to 1.4 bar) 20 to 80 psig (1.4 to 5.5 bar)
12 3P8847 08012 15 2B7974 08012 3B9855 000B2 1U9186 09012
20
1U9188 000A2 1V1077 000A2
1B7980 000B2 1B7980 000E2 1B7985 25062
1B9860 27212 1B7883 27022
21
1K7485 27202
22* 23*
1B9860 27212
24
1B9883 27022
25 26
1K7485 27202
1A9463 24112 Machine Screw, Steel (6 req’d) 1B7839 28982 Stem Guide Assembly, SST With Nitrile O-ring 1P8454 000S2 With Viton O-ring 1P8454 X00A2 Paper Label (not shown) Standard 5 to 18 psig (0.3 to 1.2 bar) 1V6736 06032 18 to 30 psig (1.2 to 2.0 bar) 1P8459 06032 30 to 100 psig (2.0 to 6.9 bar) 1V6737 06032 Panel Mounted 5 to 12 psig (0.3 to 0.8 bar) 1V6736 06032 12 to 12 psig (0.8 to 1.4 bar) 1P8459 06032 20 to 80 psig (1.4 to 5.5 bar) 1V6737 06032 Bracket, Steel (not shown, panelmounted only) T10210 25072 Gasket, Asbestos 1C4957 04022 Gasket, Asbestos 1U1716 04022
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Fisher Controls
20A7309-B
Figure 4. Type 167A Valve Assembly
Valve Plug Spring, SST 1U9189 37022 Retaining Ring, SST 1U9190 28992 Screw, Steel (2 req’d) (not shown, panel mounted only) 1B8774 28992
While this information is presented in good faith and believed to be accurate, Fisher Controls does not guarantee satisfactory results from reliance upon such information. Nothing contained herein is to be construed as a warranty or guarantee, express or implied, regarding the performance, merchantability, fitness
Printed in U.S.A.
Part Number
or any other matter with respect to the products, nor as a recommendation to use any product or process in conflict with any patent. Fisher Controls reserves the right, without notice, to alter or improve the designs or specifications of the products described herein.
For information, contact Fisher Controls: Marshalltown, Iowa 50158 USA Cernay 68700 France
Sao Paulo 05424 Brazil Singapore 0512