High Pressure Tube Fitting

[TEV]

We have a new high pressure stainless steel tube fitting for use with hard drawn or thick walled SS tubing in sizes 1/4, 3/8 and 1/2 inch. The design provides an easily made leak-tight connection at pressures up to 15 ksi with a safety factor of four. We don't have a very good handle on the market for this product, however. Specifically, where are high pressure fittings in these sizes used in petroleum recovery, refining and chemical processing, and what specifications are customarily applied? ASME/ASTM? MR0175? MR0130? What applications are there outside of the petrochem industry? What specs apply in these instances? Is the safety factor of 4x used in all these applications? The current product is in 316 stainless; are there other alloys that would extend the applications/markets for this product? If there are any user or engineering specialists who would be willing to discuss this with me directly, I would appreciate hearing from you.

 

[JLSeagull]

The low density polyethylene process from an earlier era operated around 55000 psig. Some requirements included business Check into ASME B31.3, Chapter IX, section K323.1.2 for “Unlisted Materials” and section K323.3 “Impact Testing Methods and Acceptance Criteria”. Review ASTM A705 and ASTM A564.

The chip makers use toxic materials and may use high pressure fittings. However, high pressure is more common in the petrochem business.

Most oil and gas applications are limited to below 15000 psig.

Autoclave Engineers offers products rated to 150000 psig.

http://www.autoclaveengineers.com/index4.html

Swagelok make fittings to about 60000 psig.

http://www.swagelok.com/downloads/webcatalogs/EN/MS-01-34.pdf

 

[moltenmetal]

Most of the business is 3000 psig and below, and there are plenty of suppliers who offer products in that range. Once you're beyond 2500# flange class, you're into expensive equipment. Much process development effort goes into keeping pressures lower than 2500# class.

Higher pressure users would include systems like high pressure hydraulics, supercritical fluid extraction, water-jet cutting machinery and down-hole/subsea applications. The market is more limited, but there are established suppliers in this range also.

Beyond 15,000 psig you're generally into "cone and thread" type connections for tubing. From 6,000 to 15,000 psig there are existing fitting designs which do not require the additional labour/effort of cone and thread.