NP Thread?
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Rccrawlerguy
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Found adapters to BSTP Think I’ll try the NPT and see how that goes. Only 3000psi!
RoninB4
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-Thread pitch for 1/4" NPT is 18 TPI and thread angle is 60°. If your pressure switch thread geometry is BSPT (JIS B 0203 for tapered pipe @ 55° and 19 TPI) then they may very well seem to fit together due to the thread angle difference but I wouldn't expect them to seal properly. Excessive tightening to attempt sealing may also deform the threads in the switch. "Only 3000 psi" so what could go wrong? Your call.
-If made in China they did alter the standard thread pitch to be NPT compatible a while ago but reports I've read advise to test anything made in China before acceptance/purchase.
-If made in China they did alter the standard thread pitch to be NPT compatible a while ago but reports I've read advise to test anything made in China before acceptance/purchase.
rlitman
Well-known member
Before I searched out specs for the part you displayed, I did some searching for Japanese NP thread, and that was pretty misleading, because the thread ending in "P" is likely to be BSPP (i.e. parallel and not tapered thread), which is an entirely different animal.
Now look at this listing:
It says Connecting Type: PT1/4 Thread
And when I search that out, I find out that JIS type PT thread is for your purposes BSPT.
Thread Type Guide: NPT, BSP, JIS, SAE, Metric – Trimantec
So you finally found the right solenoid valve to replace your broken one. You call to check stock on the item and the sales rep asks you what thread type you need. You ask, “How do I find out what thread type I need?” Fortunately, we’ve got you covered.
trimantec.com
You will need an adapter. And for more information on that:
Note that the above diagram shows either 1/2 or 3/4 threads, where the pitch is 14 TPI for both BSP and NPT. In 1/4" pipe threads, the two systems use different pitches from each other, so while you may be able to get helical leak sealing with a lot of sealant in 1/2 or 3/4, at 1/4 you will not get full thread engagement, so you have bigger problems that just sealing.
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txvwnut
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You smear enough JB Weld on the threads and it should seal right up, after 24 hours of set time.
BigMike782
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txvwnut
Well-known member
Honestly I haven't tried it for that... yet. But I did have a friend of mine set 2 NHRA I-gas records with JB Welded ports in his cylinder heads.How's that JB weld holding the main bearings in the rattled out air cooled case?
danielbuck
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I have a japanese diesel engine that had BSPT threads for some of the oil fittings, drove me a bit nuts till I figured out what they were.
Firebrick43
Well-known member
You are not getting an analog section on your PLC?
The IDEC smart relay is supposed to have 4 inputs that can be configured for analog. I have not used this feature before but it looks pretty straight forward.
My first time running into this. Very frustrating! But even at 53 I can learn new tricks. I find it hard to believe that I’ve never ran into this before or even knew about it!
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Firebrick43
Well-known member
Are you going to run any kind of HMI?
Is so a transducer could give a an on screen readout of the pressure thru the analog inputs of the smart relay
As far as BSPT/whitworth, the Germans use it extensively for compressed air (G1/8, G1/4, G1/2) mainly but some hydraulics but they tend to use metric ports for hydraulic.
The japanse use whitworth threads a lot in both air and hydraulic fittings. They have two or three standards of hydraulic fittings with it.
Are you going to run any kind of HMI
Not sure what that is? Really just looking to turn off a pump at a given pressure. I’ve alwas just made programs,usually with air cylinders with magnetic pickups to show position. I haven’t worked with analog signals.
Not sure what that is? Really just looking to turn off a pump at a given pressure. I’ve alwas just made programs,usually with air cylinders with magnetic pickups to show position. I haven’t worked with analog signals.
Firebrick43
Well-known member
HMI = Human Machine Interface aka a screen, sometimes even a touch screen that can display information such as position or pressure.
Turning off the pump? Why not have a solenoid valve that shuts off and kills the flow when the pressure in the cylinders circuit is made? Then you don't have to turn back on the pump to retract?
I literally first heard about this this week by coincidence.
I was watching a youtube video of creator I like that was fixing a beat down used CNC machine he bought. He specifically said the different threads look the same and will screw into each other and leak. He was mentioned he specifically bought adapters and if you didn't know it would drive you crazy.
He also mentioned there is something similar for flared and hydraulic fittings that would also give you grief.
It’s a one way pump. Solinoid valves built in. Not 100%. Still waiting on the pump unit.