I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 1 SERIES 4000 PRESSURE TRANSMITTER INSTALLATION AND MAINTENANCE INSTRUCTIONS © 2013 Ashcroft Inc., 250 East Main Street, Stratford, CT 06614-5145, USA, Tel: 203-378-8281, Fax: 203-385-0402, www.ashcroft.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 2 TABLE OF CONTENTS GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . 3 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ambient Conditions . . . . . . . . . . . . . . . . . . . . Steam Pressure Measurement . . . . . . . . . . . . Pressure Connection . . . . . . . . . . . . . . . . . . . Air Connections . . . . . . . . . . . . . . . . . . .
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 3 GENERAL DESCRIPTION Ashcroft Pressure Transmitters, Series 4000 (refer to Fig. 1), are self-nulling, motion balance instruments. They utilize a non-bleed force balance, pneumatic relay to convert input pressure into proportional low air pressure, for transmission to remote indicators or controllers.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 4 INSTALLATION Mounting Steam Pressure Measurement Ashcroft pressure transmitters are designed for bracket mounting (refer to Fig. 4), to ensure free action of all components, thereby maintaining accurate calibration. The transmitters may be pipe mounted, wall mounted or stem mounted. Typical methods of mounting are shown in Figures 4 and 5. Applicable dimensions are given in the illustrations.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 5 Air Connections Connect the LOW pressure instrument air SUPPLY to the 1⁄4 female NPT connection, marked SUPPLY, at the left of the process pressure connection. The instrument air is to he clean, dry, and liquid free. Connect the remote equipment line to the 1⁄4 female NPT connection, marked OUTPUT, at the right. The use of metal or plastic tubing in place of piping is strongly recommended.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 6 THEORY OF OPERATION Input Element Pneumatic Relay The input element of the pressure transmitter is a pressuresensitive bourdon tube. As mounted in a transmitter, increasing pressure raises the free end of the bourdon tube, while decreasing pressure lowers it. The height of the free end with respect to any fixed reference point is, therefore, a direct measure of internal pressure.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 7 Figure 7.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 8 TROUBLESHOOTING GeneraI Note: Since most pressure take-offs are dead end service, with resultant cooling, it is unlikely that the transmitter itself will be subjected to temperatures exceeding 150°F, except in extreme cases. Many complaints of faulty transmitter operation have, on investigation, proven to be due to faulty installation.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 9 REMOVAL AND REPLACEMENT OF PARTS General Note: On indicating pressure transmitters, break adhesive bond by heating nut (5) securing zero adjusting assembly and remove nut and zero adjusting assembly. On short span pressure transmitters, remove vane assembly (3a) by removing two screws (4b). The assemblies and parts illustrated in Figures 8 and 9 and listed in the Parts List are available for replacement purposes.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 10 Figure 8.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 11 Figure 9.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 12 CALIBRATION General n. Move span adjusting disc (10) on nut assembly (9) toward bellows if receiver gauge indicates less than full scale indication desired (15 or 27 psig). Move range adjusting disc away from bellows if receiver gauge indicates above full scale indication desired. Calibration of the transmitter Is very similar to calibration of a gauge.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 13 Figure 10.
I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 14 PARTS LIST ITEM 1 1a. 1b. 1c. 1d. 1e. 1f. 1g. 1h. 1j. 1k. 1l. 2 3 4 4a. 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 22a. 22c. 22d. 22e. 23 23a. 23b. 24 25 26 27 28 NAME OF ASSEMBLY OR PART Base Plate Assembly Plate Clamp Assembly Adapter Nut Gasket Filter Screw Washer Lock Washer Flat Cap Screw Connector (Tubing) System Zero Adj.
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I&M008-10061-1-01 250-1969-C_I&M008-10061-1/01 250-1969-C 12/20/13 9:09 AM Page 16 Global Headquarters Ashcroft Inc. 250 East Main St. Stratford, CT 06614-514 Phone: 203-378-8281 For access to our global web sites, additional products/specifications and a complete list of our operations, sales offices, distributors & reps visit: www.ashcroftinc.com Visit our web site www.ashcroft.com All specifications are subject to change without notice. All sales subject to standard terms and conditions.
