The comparative inflexibility of the

heavy-walled tubing

must be taken into consideration when designing high-pressure tubing systems.
One-fourth inch tubing can be bent cold by clamping it in a smooth-jaw machinist vise and slipping a piece of pipe (the end of which has been fully beveled to prevent nicking or scratching of the pressure tubing) over the free end of the tube. By using a pipe as a lever, the tubing can be bent to the required angle. In some instances a loop similar to an expansion bend in pipe line is formed in the tubing to allow flexibility in assembling and dismantling. The 1/4 inch o.d. tubing can be bent on 1 inch radius without flattening of the cross section. Where the 1/4 inch o. d. tubing is used in temporary installations with the expectation of the subsequent re-bending to other dimensions, the radius of bend should be at least six times the outside diameter of the tube.
Three-Eighths and 9/16 inch o. d. Superpressure tubing can be bent. Although it is a difficult task, this process is frequently economical when suitable equipment is at hand. When accurate alignment is required and distances are short, it is preferable to use SUPERPRESSURE ELBOWS instead of bending 3/8 and 9/16 inch o.d. tubing.
Provisions must be made for the expansion of heated tubing since the tubing is rigid enough for heat to create severe stresses. Both 3/8 and 9/16 inch o.d. tubing can be bent on a 2 inch and 3 inch radius, respectively. Temporary bends are not ordinarily made in 3/8 and 9/16 inch o.d. tubing since subsequent bending may weaken the tubing.
All joints or connections are made with the
SUPERPRESSURE FITTINGS . To connect the tubing and fittings, the ends of the tubing must be prepared, by first turning the end to a cone, and second, by threading the end with a left hand thread to take the inner sleeve of the coupling, Please click for  SUPERPRESSURE TUBING TOOLS FOR PREPARING SUPERPRESSURE TUBING  details.