MIL-G-2860E, MILITARY SPECIFICATION, GLASS, SIGHT, FLAT, CLEAR, BOROSILICATE (30 DEC 1977)

MIL-G-2860E, MILITARY SPECIFICATION, GLASS, SIGHT, FLAT, CLEAR, BOROSILICATE (30 DEC 1977)., This specification covers thermally tempered borosilicate sight glasses for such services as viewing the operation in water evaporators and turbine oil sight-flow indicators where the temperatures do not exceed 400 deg. F and 50 pounds per sqaure inch (psi) pressure.