This Defence Standard (Def Stan) 02-797 Part 4 details the approved method of making breakable connections, by the use of screwed couplings and compression type fittings, for Low Pressure (LP) and High Pressure (HP) Systems in HM Surface Ships and Submarines.

This Def Stan is to be read in conjunction with Def Stan 02-324 Part 1 and Def Stan 02-797 Part 1.

WARNING – Pressures in excess of 6.9 bar (100psi) can puncture the skin and soft tissue causing injury. Any injuries sustained will require immediate medical assistance. Fluid-injection injuries shall be treated without delay and shall not be treated as a simple cut.

Any fluid injected into the skin shall be surgically removed within a few hours, or gangrene can result. Doctors unfamiliar with this type of injury should consult a knowledgeable medical source.

Fine streams of escaping pressurized fluid can penetrate skin and enter a human body. These fluid injections can cause severe tissue damage and loss of limb. Various means shall be taken into consideration to reduce the risk of fluid injections, particularly in areas normally occupied by operators. Such means include: careful routing of hose, adjacent components, warnings, guards, shields and training programs. Pressure shall be relieved before disconnecting hydraulic or other lines. All connections shall be tightened before applying pressure. Contact with escaping fluids shall be avoided.

All leaks shall be treated as if they were pressurised and hot enough to burn skin. No part of the human body shall be used to check a hose for leaks. If a fluid-injection accident occurs, medical treatment by a doctor shall be sought immediately.