The issue of selecting an 800LB pressure rating for the design of small-diameter valves
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Why do design institutes choose 800LB grade drain valves for sizes below DN40? What are the advantages of this, and are there any relevant standards that specify it? Friends are welcome to share their insights
These are welded valves, with a minimum weight rating of 600LB, offering high weld strength.
We use it for 2.4MPA medium-pressure steam drain valves; 300lb should be sufficient. I’m not sure if the price of 800 is similar to that of 300, so we decided to choose 800 for the design
There are no welding drain valves available in 300LB rating; the minimum rating is 600LB. For 2.4MPa steam, an 800LB one should be selected. Thicker.
There is indeed no 300lb rating in the American standards
For small-diameter socket weld connections. Usually, whether it’s 150LB or 300LB, an 800LB one is used.
I just want to know the reason, why? If it’s a stainless steel valve, doesn’t the cost increase significantly?