Product Data TEMPERATURE PRODUCTS Model TW-STEP General Use Thermowells DESCRIPTION U.S. Gauge recommends the use of a thermowell in conjunction with a bimetallic thermometer when the application involves a corrosive medium, high pressure, or high flow velocity. Some specific uses include protection for unarmored liquid-in-glass test thermometers or other temperature sensing elements with a maximum diameter of .25". LENGTHS: ±1/16" on lengths 12" or less; ±1/8" on lengths 12" or over These #20 gauge bimetallic thermowells meet or exceed SAMA specifications and are also available in heavy duty, flange, socket weld, and Van Stone models. Standard thermowells are stepped to 1/2" OD, except for 2-1/2" insertion. Straight shank models are also available. BORE ID: +.005; -.003; usually within ±.002 The standard process connection sizes are 1/2-14 NPT and 3/4-14 NPT, with other sizes available. Materials of construction include 316L stainless steel (standard), 304 stainless steel, and brass (ASTM B-16). A cap and chain for keeping the thermowell bore clean when not in use are available upon request. WELLS 30" AND OVER: Solid bored type will be drilled thru end, plugged, and heli-arc welded; built-up design must be specified beyond 42-1/4" overall length OD TOLERANCES: Fractional: ±.015; Decimal: ±.005 on .000 place; ±.01 on .00 place END THICKNESS: Gun drill bottom; 1/4" to bottom ±1/16"; 3/16" minimum end thickness CONCENTRICITY OF BORE TO OD: ±10% of minimum wall thickness WETTED SURFACES FINISH: Standard finish 60-100 Ra; 16-32 Ra available; 4-10 Ra mirror polish available RADIUS UNDER THREADS AND FLANGES: 1/8" is standard, ±1/16".; 1/16" on Van Stone type MALE THREADS (NPT): ±1 turn on thread gage FEMALE THREADS: 1/2" NPSM standard; 1/2-14 NPT available upon request; go gauge to 5/8" depth of thread; no go gauge 2 turns maximum END OF WELLS: Break corners; no burrs LAGGING EXT.: On screwed wells; left as hex stock (not turned); exception – when hex is not available in special materials STAMPING: Stamped onto hex or round facing open end of well; material code identification; tag numbers Model TW-STEP FLANGED WELLS: Made in accordance with ANSI B16.5; raised face is serrated 125 Ra; smooth face must be specified on order if needed FRONT J: Groove welds are 1/4" wide by 1/4" deep; welds are machined, leaving 1/8" radius; rear welds are 1/8" wide by 1/8" deep V; welds are machined, leaving 1/4" radius; full penetration welds are available upon request and must be specified Dimensions Model Process Connection Shank Diameter Q INCHES (MM) 1.75 (44.5) U = INSERTION LENGTH 1.0 (25.4) THREAD ALLOWANCE On-line order fax: +1 215-323-9450 or e-mail: [email protected] Sales/Technical Support: +1 215-293-4100 | 205 Keith Valley Road | Horsham PA 19044 U.S.A. © 2013, by AMETEK, Inc. All rights reserved. Printed in the U.S.A. PDF513 (160174) Specifications are subject to change without notice. Visit our Web site for the most up-to-date information.

Product Data TEMPERATURE PRODUCTS Model TW-STEP General Use Thermowells Spec Number Selection Chart Model TW – General Use Model TW – Lagging Extension Model TW – General Use, Heavy Duty Model TW – Lagging Extension, Heavy Duty Model TW – Limited Space 2-1/2" Stem Length Spec No. On-line order fax: +1 215-323-9450 or e-mail: [email protected] Sales/Technical Support: +1 215-293-4100 | 205 Keith Valley Road | Horsham PA 19044 U.S.A. © 2013, by AMETEK, Inc. All rights reserved. Printed in the U.S.A. PDF513 (160174) Specifications are subject to change without notice. Visit our Web site for the...