I have a simple but question that has puzzled me for a long time
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This post was last edited by belarl on 2016-1-21 at 15:14. It’s a regular manual valve, such as the Q11F-16 model, with a specification of DN15 and a connection diameter of G1/2. However, when installing it, I have two types of pipes, both of which are DN15; one has an outer diameter of 21.3 and the other has an outer diameter of 18. I want to know whether the Q11F-16 can be used with both types of pipes. Also, what should be the minimum wall thickness for these pipes? It would be best if you could give me a universal answer that applies to other valves and piping as well, not just this particular valve. In other words, I want to know how such threaded valves should be matched with the corresponding piping, and what standard of piping should be used
It seems it can’t be explained in just two sentences:) Waiting for an expert
Valves can be directly fitted on those with an outer diameter of 21.3; for those with an outer diameter of 18, flanges and adapter fittings are required to install the valves.
Your question relates to our country’s pipeline series (Series I and II). For information on pipe series, you may refer to the explanatory notes in HG/T 20553-2011 \"Series for Selecting Dimensions of Seamless and Welded Steel Pipes for Chemical Piping\". For DN15 pipes, those with an outer diameter of 21.3 belong to series Ia, while those with an outer diameter of 18 belong to series II. When working on projects that involve pipes, it is necessary to first determine the pipe series to be used (DNXXX, DNXXX(Ⅱ)). If not specified, the series Ia is assumed by default. The selected pipe fittings (valves, flanges, elbows, tees, reducers, etc.) must be marked with a series number after DNXXX. For your reference
Because of standard issues. 21.3 is a PIPE pipe, belonging to the British standard DN15, that is, a 1/2 inch pipe. And 18 corresponds to the metric pipe fitting specification of DN15 in the metric system. This is why Class A and B designs are used in seamless fittings, to accommodate both metric and imperial pipes
May I ask how the series number is added after DN×××, which is indicated on fittings, valves, tees, etc.? Could you give an example? For instance, if I choose a pipe of the IA series with a DN15 diameter, and the corresponding ball valve is Q11F, how should the complete model number of this ball valve be expressed? I chose pipes of the IB series with a DN15 diameter, and the corresponding ball valve is Q11F. How should the complete model number of this ball valve be expressed? I chose pipes of series II with a DN15 diameter, and the corresponding ball valve is Q11F. How should the complete model number of this ball valve be expressed?
Q11F-XXX DN15（ⅠB）. For reference
Is the Ia series commonly used? It seems to me that we usually use the II series (which are mostly for water pipelines)