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Sprinkler Valve Questions

Posted: Sun Jun 01, 2008 10:51 pm
by n-strike
When attaching a blowgun to a sprinkler valve, do you have to use the tap and die set to thread it? Or can you just hand thread it using the brass nipple? And also, do all sprinkler valves have female threads that you have to use nipples on? Or are some just slip? Thanks for your help!

Posted: Sun Jun 01, 2008 10:55 pm
by BC Pneumatics
PVC is soft enough to tap with the fitting, but if you plan on tapping more than two or three holes in your lifetime, I suggest you invest in a tap, it is well worth it. They cost less than $10 and make clean, strait threads quickly and easily. Most every model of sprinkler valve I have seen is available in both NTP and Slip styles.

Posted: Sun Jun 01, 2008 10:57 pm
by Darkside 6ix
look at the sprinkler "how-to" guide. You basically drill a hole for a 3/4 nipple and then thread it your self. To make it easier on the hands, stick the nipple on the drill and pretend like its a drill bit.

Posted: Sun Jun 01, 2008 11:01 pm
by n-strike
In this video: the guy drills a 1/2" hole, but uses a 1/4" nipple. Why is that? And also, you know how there's a hole in the blowgun to attach it to the nipple? How do you know what size the hole is? Thanks again.

Posted: Sun Jun 01, 2008 11:05 pm
by BC Pneumatics
1/4" pipes are close to 1/2" in diameter. (Just as 1.5" PVC has a 1.9"OD) The correct size hole for tapping 1/4" NPT threads is 7/16", though without a tap 1/2" may be necessary. In America pretty much every air tool is 1/4", hose threads are 1/4", and accessories, including blowguns, are 1/4". Just the way it is, so no need to check.

Posted: Sun Jun 01, 2008 11:08 pm
by n-strike
Okay. And one last thing...(unless I have more question, which I probably will) what does NPT mean?

Posted: Sun Jun 01, 2008 11:10 pm
by BC Pneumatics
National Pipe Thread. It is type of threads that pipe fittings in the US use. They are course, tapered threads.

Posted: Sun Jun 01, 2008 11:15 pm
by n-strike
Okay, and yes I have another question. Why in the video that I put earlier is one half of the nipple smaller than the other?

Posted: Sun Jun 01, 2008 11:20 pm
by BC Pneumatics
It is a reducing nipple. One side has threads of a certain size, and the other side has threads of another size. For connecting, say, 1/2" fittings to 3/4".

Posted: Sun Jun 01, 2008 11:22 pm
by n-strike
So if I wanted to I could just get a nipple with both 1/4" sides and just use a 1/4" drill bit instead?

Posted: Sun Jun 01, 2008 11:23 pm
by BC Pneumatics
No. A nipple with 1/4" NPT threads would require a 7/16" hole. There is no common pipe thread that uses a 1/4" hole.

Posted: Sun Jun 01, 2008 11:28 pm
by n-strike
Okay. I saw another video of a guy putting a blowgun on his sprinkler valve, but the section that you drill your hole on was small for him so he had to use a smaller nipple. Also, do sprinkler valves come in different sizes? Like, say...1"?

Posted: Sun Jun 01, 2008 11:31 pm
by BC Pneumatics
Yes, they come in <a href="http://www.bcarms.com/product_info.php? ... id=32">one inch</a>, and many other sizes. 3/4", 1", 1.5", 2", and 3" are the most common, though anything over 1" is rather expensive, and tricky to find.

Posted: Sun Jun 01, 2008 11:36 pm
by n-strike
Okay. Thanks for all your help! I just wanted to make sure about everything before I purchase one. It's my first time using a sprinkler valve. I've always used ball valves because I was inexperienced and I didn't have much money. But now that I have money, I can purchase a sprinkler valve and make a monstrous pneumatic over under 4" cannon!

Posted: Sun Jun 01, 2008 11:38 pm
by BC Pneumatics
A sprinkler valve is not recommended for anything over 2.5", since the flow is really too weak. I suggest using multiple valves, or switching to a design that uses a piston valve or burst disk.