Help with selecting a safety valve
Thread Content
:We have been using safety valves for the primary and secondary economizers of our medium-pressure waste heat boilers for half a year; two of them have already been replaced. Now, these safety valves are leaking. The original models were A48Y-100 DN80, semi-enclosed type. Every time they triggered and then closed, it would wet our clothes completely, and there was also a risk of burns. We would like to replace them; please help us choose a suitable model. Medium: deoxygenated water, pressure 5.7 MPa, start-up pressure 6.38 MPa, temperature 240 degrees.
Please check the valve selection manual; in any case, for safety valves used with steam or other gases, those equipped with a wrench (testing wrench) are the right choice. It is likely that the leaks occur because the sealing surface of the cemented carbide is of poor quality; find a manufacturer with better quality – it’s necessary to be willing to spend more money and afford to buy higher-quality products. Regarding the issue of closing valves in case of leaks, it is recommended to attach a extension pipe of about 3 meters behind the valve, directing the exhaust outlet to a location where it poses no danger to people or equipment. When the exhaust pipe is laid horizontally, it should have a 3% downward slope to facilitate the timely drainage of water in case of internal leaks, thereby preventing freezing in winter.
What does the third floor mean, and is there any basis for it?
Can’t you run a pipe from the safety valve outlet to an uninhabited area? Why do I get drenched every time I jump? Also, you changed them twice in half a year – that seems a bit odd. What was the reason for those changes?
Regardless of whether it’s related to the type of safety valve or a piping issue, install a section of pipe at the outlet of the safety valve, mainly to prevent water from splashing out after it activates.
It is estimated that the fluctuations in your economizer section are quite large, causing damage to the cemented carbide on the sealing surface.
Use a closed type; do not use A48Y for those that handle liquids
Use A42Y-100 DN80