Page 1 — Type 92P
I N S T R U C T I O N S a n d PA R T S L I S T Type 92P TYPE NUMBER EXPLANATION The Type 92P is an air loaded steam pressure reducing valve which is pressure balanced. It can be used on any steam application within its pressure range and capacity. PRINCIPLE OF OPERATION Refer to the schematic illustration in Figure 1. When operation begins the manual loader loads pressure on diaphragm “H” causing it to oppose spring “E” and tending to open valve “D”, allowing steam to flow downstream. The downstream pressure registers under the main diaphragm through control line “J” and tends to balance the diaphragm. As the downstream pressure builds up, the pressure on the bottom side of the diaphragm approaches the pressure on the top, tending to close the valve. When steam demand increases, the downstream pressure decreases, thus decreasing the pressure on the bottom side of the main diaphragm, allowing the valve to open further. If the steam demand decreases, the downstream pressure increases and pressure is increased on the bottom of the main diaphragm, overcoming the balance and causing the valve to move towards the closed position. INSTALLATION Loading Relay — Any suitable air loading regulator such as a Fisher Type 67, 670 or 1301F Series can be used as a loading relay. It is recommended that a bleed orifice be installed in the second outlet of the loading relay.
1. Inspect the regulator for any shipment damage. Remove any foreign matter that may have collected in the regulator during shipment. 2. Blow out the pipe line wherever practical. 3. Install a strainer ahead of the regulator to protect the internal parts of the valve. 4. Install an upstream block valve ahead of the regulator so that the regulator can be isolated and serviced. If continuous operation is necessary during maintenance or inspection, install a bypass valve and piping around the regulator and a block valve in the downstream. 5. This regulator is intended to be installed with the diaphragm case above the pipeline so that condensate will not collect in thecase. 6. Install the regulator in the pipeline so that the flow will be in the direction indicated by the arrow cast on the body. Follow normal piping procedures when installing the screwed or flanged regulator. 7. Install the external control lines as follows: a) Connect one end of the control line to the tapped hole in the regulator body. This hole is located near the diaphragm case flange as schematically shown in Figure 2, and is NPT tapped to either 1/4” (for body sizes 1/2”, 3/4”, 1”, 1-1/4” and 1-1/2”), 3/8” (for sizes 2” and 2-1/2”) or 1/2” (for sizes 3”, 4” and 6”). The control line should be as large as the tapped hole in the regulator. b) The other end of the control line is connected to the downstream system. Locate the tapped hole for this connection in a straight run of pipe 3 to 5 feet from the regulator when it is the same size as the pipeline. Locate the tapped hole at CONSTANT LOADING PRESSURE
Dwg. AR6495 Figure 1 —Schematic illustration of Type 92P. PRINTED IN U.S.A. 5—5-69 JSS
FISHER CONTROLS COMPANY
Marshalltown, Iowa
Coraopolis, Pa.
Woodstock, Ont., Can.
Toluca, Mexico
FORM 1889A (Supersedes Form 1889)