Customer Service Hotline:13585310218

Welcome to our website   WEBSITE 



Products are widely used in different fields such as petroleum, chemical, electric power,
refrigeration, food, medicine, etc.



One-piece rubber hydraulic expansion rod

Page view
Publish time
product description

Easy to replace, save time and effort, and reliable quality!

(1) Instructions for use of the expansion rod

1. Before the expansion, the sharp mouth or burr of the end of the heat exchange tube must be removed to avoid damage to the liquid bag.

2. Before installing or replacing the expansion rod, use a syringe or other method to fill the expansion rod with water or the selected expansion medium to remove the air inside the expansion rod.

3. Whenever the expansion rod and hose are replaced, the air in the ultra-high pressure system must be emptied and the expansion medium should be replenished in time to avoid affecting work efficiency and ensuring safety.

4. Before the formal expansion, the no-load start, so that the hydraulic circuit of each hydraulic system is fully circulated for 5-10min.

5. When the expansion joint is connected, the extension line of the heat exchanger expansion joint (opposite the heat exchanger) shall not stand, otherwise the steel plate or other methods shall be used for protection.

6. For the nozzle that can not be inserted into the partial expansion rod, the defects such as the tube burr and the welding tube can be treated first. After the treatment is invalid, the expansion rod can be fully ground and then inserted into the cylindrical grinding machine, but the inner diameter of the tube and the expansion rod The gap between the outer diameters does not exceed 0.3 mm, and the outer diameter of the expansion rod will affect its service life.

7. When inserting or pulling out the expansion rod, it is strictly forbidden to twist the expansion rod.

8. It is forbidden to expand the joint before the expansion rod is inserted into the tube hole or not fully inserted into the tube hole, so as not to damage the expansion rod.

9. During the operation of the expansion tube, the expansion head must be pulled out after the pressure is completely relieved. If the expansion rod is not fully removed before the pressure is removed, the expansion rod will be seriously damaged.

(2) Service life

1. The life of the expansion rod is realized by controlling the total gap (the gap between the inner diameter of the tube sheet hole and the outer diameter of the heat exchange tube and the gap between the inner diameter of the heat exchange tube and the outer diameter of the expansion rod) between 0.6 and 0.8 mm.

Therefore, the total gap <0.6mm, the life will be longer; the total gap>0.8mm, the life will be reduced; the total gap>1mm, the life will be lower.

2, the life of the expansion rod is an average, the same size, the greater the number, the longer the average life, the shorter the opposite, the less than 10 can not ensure the life; the different diameters, the longer the average life, On the contrary, the shorter the length; the longer the expansion rod, the shorter the average life, and vice versa.

3. When the strength expansion joint is implemented, both sides of the expansion rod liquid bag (rubber part) must be controlled more than 8mm from the edge of the tube plate groove, and the edge of the liquid bag edge is tightly swelled in the groove, otherwise the expansion rod life will be seriously affected. .