Pressure Vessels Selection Guide

Need help picking out a pressure vessel? Visit our new Pressure Vessels Selection Guide.

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Parr Instrument Company 211 Fifty Third Street
Moline, Illinois 61265-1770
(800) 872-7720 or
(309) 762-7716
Fax: (309) 762-9453

Coned Pressure Fittings

Gage Blocks, pressure hoses and other parts that are frequently removed from a pressure vessel are attached with a coned, socket type connector. The male segment of a coned fitting consists of a sleeve with a left-hand thread screwed onto a thick-walled tube, plus a compression nut to complete the assembly. When screwed into a matching socket these parts produce a rigid joint which will remain tight over a wide temperature and pressure range, yet the joint can be made and broken repeatedly without destroying the sealing faces. No gasket or sealing tape is required. These fittings have the added advantage of behaving like a union fitting, allowing the gage block, connecting tube or hose to remain stationary while the nut is tightened to close the joint. Parr coned pressure fittings are made in two sizes, identified as types ‘A’ and ‘B’, for 1/4 inch and 3/8 inch tubing, respectively.  

Coned Pressure Fittings
Type A B
Tube Size 1/4 in. 3/8 in.
Thread (D) 9/16 -18 3/4 -16
Bore (E) 3/32 in. 1/8 in.
Nut No. 35HC 326HC
Sleeve No. 40HC 366HC
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