Flange gaskets above 2.5Mpa are all made of metal wound […]
Flange gaskets above 2.5Mpa are all made of metal wound mats.
1.0Mpa-2.5Mpa flange seal with asbestos pad and black lead powder.
The water pipe flange gasket below 1.0Mpa is made of rubber pad and painted with black lead powder.
The packing of the pump is made of PTFE composite packing.
The sealing parts of the smoke and wind coal pipes, the asbestos rope used is twisted once and flat, and the joint surface is added. It is strictly forbidden to tighten after tightening the screws.
Prevent leakage inside the valve
Pipe installation and construction, establish a good quality awareness, consciously clean the iron oxide skin and the inner wall of the pipe, leaving no debris, to ensure that the inner wall of the pipe is clean.
First, ensure that the valve entering the site is 100% hydraulically tested.
Valve grinding should be carried out conscientiously. All valves (except imported valves) are required to be sent to the grinding class to dismantle the inspection and repair, and to implement the responsibility, and consciously make records and marks for easy traceability. Important valves should be listed for detailed inspection and acceptance, so as to achieve the requirements of “printing, printing, and recording”.
The boiler's first water supply gate and discharge door should be determined in advance. Only during the hydraulic pressure test, these valves should be opened. Other valves should not be opened at will, thus protecting the valve core.
When the pipe is flushed, it should be opened and lightly closed to prevent damage to the door core.
What if the valve has leaked?
The casting quality of cast iron parts is not high, and there are defects such as sand holes, loose structures and slag inclusions on the valve body and the valve cover body;
Poor welding, there are defects such as slag inclusion, unweld, stress cracking;
The cast iron valve is damaged by heavy objects.
Improve the quality of casting, and carry out the strength test in strict accordance with the regulations before installation;
For valves with temperatures below 0 °C and below 0 °C, heat or heat should be applied. Valves that are stopped should be drained;
The welded joints of the valve body and the valve cover composed of welding shall be carried out in accordance with the relevant welding operation procedures, and the flaw detection and strength test shall be carried out after welding;
It is forbidden to push and push heavy objects on the valve. It is not allowed to hit the cast iron and non-metal valves with a hammer. The installation of large-diameter valves should have a bracket.