API Recommended Practice 7HU1

Safe Use of 2-inch Hammer Unions for Oilfield Applications

This recommended practice (RP) sets forth procedural recommendations as well as an engineering solution to the mismatching of the most common hammer unions used in oilfield applications. The mismatching of hammer union components is a worldwide issue in the industry and can cause serious incidents. Complete and proper make-up of hammer union components is required to attain the rated working pressure of the equipment. The procedural recommendations described in this RP should be implemented to reduce further incidents.

The engineering solution applies to the manufacture of new hammer union components and should not be applied in the modification of existing hammer union components due to unknown factors caused by field wear.

First Edition
May 2009
Price: $35.00
12 Pages

Available through IHS:

Phone Orders: 1-800-854-7179
(Toll-Free in the U.S. & Canada

Local and International: 303-397-7956

Fax Orders: 303-397-2740

Online Orders:     
API Publications e-store

API Members receive a 30% discount where applicable.