PT&P specially designed twelve Type “F” variable spring hangers (4-160-F, 8-170-F, 8-180-F) for an oil refinery in Indiana. These variable spring hangers were custom designed to support a Hydro-Test load 4.5 to 5 times the design load, which ranged from 7,988 lbs. to 13,075 lbs. The spring rates of the variable spring hangers ranged from 500 lbs./in. to 750 lbs./in. with travels of 1.15” to 2.82”, upward movement respectively. The locking devices for these springs were manufactured using basic materials (rods, hex nuts and heavy pipe wall) and a special pressure plate to accommodate the application design criteria requested by the client. The base plate designed for these F- Type cans was modified to accommodate the locking devices.