Why impact methods are hazardous
When using a sledgehammer, the operator stands close to projecting parts of the connection. The tool can slip, injure hands, release metal fragments or damage the nut lugs.
Repeated impacts also make applied force difficult to control. Overtightening can complicate later dismantling, while damage to the connection surface can increase the risk of an in-service defect.
What a purpose-designed wrench offers
A purpose-designed wrench engages the hammer union nut and allows controlled force to be applied without striking. Selection depends on the connection type, outside dimensions, available working space and required drive.
Before work begins, depressurise the connection, clean the mating surfaces and inspect the tool. Trained personnel must follow the site's procedures.
Information for tool selection
- hammer union type and size
- photographs of the connection and available working space
- operating conditions
- whether manual, hydraulic or another drive is required