How to Check the Pressure of a Hydraulic Butt Fusion Machine?

The pressure gauge on the manifold block indicates the pressure of the carriage valve. How much pressure depends on the position of the selector valve and the pressure set on the specific pressure reducing valve. With the selector valve up, the facing pressure can be set. It may be necessary to adjust the carriage speed, while facing, with the top pressure reducing valve to control facing speed.

Shift the selector valve to the center position, heating, and set the pressure reducing valve at its lowest setting, or the drag pressure, whichever is higher. With the selector valve in the down position, the fusion pressure can be set.

An approximate 2 Bar (30 psi) drag factor should compensate for seal, and pipe drag with one joint of pipe on a pipe stand. If additional lengths of pipe are being moved by the movable jaws, the actual drag pressure should be determined using the following procedure:

(1) After facing the pipe, move the carriage so that the pipe ends are approximately 50 mm (2”) apart.

(2) Shift the carriage control valve to the middle (neutral) position, select the heating mode, and adjust the middle pressure reducing valve to its lowest pressure by turning the valve counterclockwise.

(3) Shift the carriage control valve to the left. 

(4) Gradually increase the pressure by turning the heating valve clockwise.

(5) Increase the pressure until the carriage moves.

(6) Quickly reduce the heating pressure valve counterclockwise until the carriage is just barely moving.

(7) Record this actual drag pressure.

(8) Take the pressure, determined from the Fusion Pressure Calculator, and add the actual measured drag pressure. This will be the actual fusion pressure to set with the bottom pressure reducing valve. If fusion pressures are used from the reference section, you must subtract 2 Bar (30psi) drag, which is already figured in, and then add the actual drag pressure back.

(9) Adjust the middle heating valve to show recorded drag so that pipe ends will stay in contact with the heater during the heating phase.

Through the above steps, we can correctly measure the actual resistance of the hydraulic butt welding machine to ensure a smoother welding result. As an expert in hydraulic butt welding machines for many years, RIYANG can give you some professional advice to a certain extent.

As an experienced butt welding machine manufacturer, RIYANG has won unanimous praise from many customers with its excellent R&D technology and leading manufacturing process. In order to strictly control the quality of products, we are equipped with a professional quality inspection system and a comprehensive management team. We always put the needs of customers first, so we can also provide users with effective solutions technology and thoughtful one-stop service. If you want to buy our butt welding machine, please contact us immediately!