I don't know what threads are used on your drain valve, but I know for sure that tolerances on China-made ''cheap'' parts are often rather loose. To give you an idea, the drain valve on my Tuxing compressor have M6 x .75 threads, but the OD of the threads is 0.010'' smaller than the nominal major diameter (0.226'' vs 0.236''). So you may well have M5 x .8 threads, but loosely made. But seeing the price these valves sell for, is it worth the hassle to make one?https://www.aliexpress.com/item/32846679999.html?spm=a2g0o.detail.1000014.60.b1c3263apWi4jB&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.33416.213724.0&scm_id=1007.33416.213724.0&scm-url=1007.33416.213724.0&pvid=18bd26bc-6fb2-46e9-9347-8d63f1747f83&_t=gps-id:pcDetailBottomMoreOtherSeller,scm-url:1007.33416.213724.0,pvid:18bd26bc-6fb2-46e9-9347-8d63f1747f83,tpp_buckets:668%230%23131923%2349_668%23888%233325%236_23416%230%23213724%230_23416%236336%2330479%231_23416%234721%2321967%23818_23416%234722%2321972%232_668%232846%238111%231996_668%235811%2327187%2379_668%236421%2330827%23688_668%232717%237566%23830_668%231000022185%231000066059%230_668%236808%2332770%23179_668%233422%2315392%23189_4452%230%23226710%230_4452%233474%2316498%23568_4452%234862%2324463%23900_4452%233098%239599%23619_4452%235108%2323442%239_4452%233564%2316062%23856&&pdp_ext_f=%7B%22sceneId%22:%2223416%22,%22sku_id%22:%2265246388927%22%7D
Quote from: happymecanic on August 22, 2021, 08:45:56 AMI don't know what threads are used on your drain valve, but I know for sure that tolerances on China-made ''cheap'' parts are often rather loose. To give you an idea, the drain valve on my Tuxing compressor have M6 x .75 threads, but the OD of the threads is 0.010'' smaller than the nominal major diameter (0.226'' vs 0.236''). So you may well have M5 x .8 threads, but loosely made. But seeing the price these valves sell for, is it worth the hassle to make one?https://www.aliexpress.com/item/32846679999.html?spm=a2g0o.detail.1000014.60.b1c3263apWi4jB&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.33416.213724.0&scm_id=1007.33416.213724.0&scm-url=1007.33416.213724.0&pvid=18bd26bc-6fb2-46e9-9347-8d63f1747f83&_t=gps-id:pcDetailBottomMoreOtherSeller,scm-url:1007.33416.213724.0,pvid:18bd26bc-6fb2-46e9-9347-8d63f1747f83,tpp_buckets:668%230%23131923%2349_668%23888%233325%236_23416%230%23213724%230_23416%236336%2330479%231_23416%234721%2321967%23818_23416%234722%2321972%232_668%232846%238111%231996_668%235811%2327187%2379_668%236421%2330827%23688_668%232717%237566%23830_668%231000022185%231000066059%230_668%236808%2332770%23179_668%233422%2315392%23189_4452%230%23226710%230_4452%233474%2316498%23568_4452%234862%2324463%23900_4452%233098%239599%23619_4452%235108%2323442%239_4452%233564%2316062%23856&&pdp_ext_f=%7B%22sceneId%22:%2223416%22,%22sku_id%22:%2265246388927%22%7DYeah I think you are right on both counts. For this part I think low tolerance probably works to safety's favor. You want it to release pressure fast. I want to test this new compressor asap so I can have recourse if there is an issue. Is your screw pointed like a pin valve or flat like the picture in your link? Does it have a relief cut in the side that helps the air escape?Thanks!
There are 2 of these so I'll have to do two. It must be high and low side?? Or maybe to look symmetrical. Can't have any "non-typical" pumps running around.
]My screw is pointed with a small flat on the end, and has a relief milled on the threads (see pic). It screws into a brass fitting like on your compressors.Don't know much about Yong Heng compressors, but a high and low side is quite plausible.Hey nice work on the steel screws! I'd recommend to mill a flat on the side to help with water and pressure release, you want the flat to reach lower than the threads root. And I'm sure you can make SS ones at a very decent price, maybe not worth it to order and wait from Ali after all .Cheers!