TnT Hydraulic connection??? BSPPM vs. NPTM

   / TnT Hydraulic connection??? BSPPM vs. NPTM #1  

teg

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So I got the toplink from surplus center, description reads that the "Ports: 3/8" BSPP" but it also says that it "Ships with two 3/8" BSPPM to 3/8" NPTM connectors". :confused:

I never used BSPP... Don't know what it looks like but when I screw in what I think is BSPP into the lock valve (labeled base in photo) It's very loose until the final turn. I feel like that will surely leak.

When I turn the connector over and use the NPTM, it feels good and tightens up as I screw it in. I am not sure which one the lock valve is threaded for... can I just screw in any 3/8" NPTF connector into the block?

Basically, in the photo, which connector is screwed in correctly? A or B?

It also seems that the swivel I plan to use really likes to screw onto what is labeled "A" BSPP.... it's really tight (just using fingers :confused2:)

PS... It was shipped with "B" threads facing out (the loose fitting way)

Link to top link:
Surplus Center - 2X11X1.18 CAT I HYD DA TOP LINK CYL
 
   / TnT Hydraulic connection??? BSPPM vs. NPTM #2  
The fitting in your hand with the cone, has a straight thread and mates with the recessed cone on the left of the picture. I believe a BSPP straight thread going into a valve or cyl needs a washer or o-ring. The NPT should go to the hose fitting.

The NPT thread will be tapered.

You might be able to screw the NPT into a BSPP thread, but it will not seal.

British Pipe Standard fittings are amongst the most popular of all foreign threads in the world today. These threads come in two versions: parallel (BSPP), and tapered (BSPT). The thread flank angle for both tapered and parallel British threads is 55°. NOTE: It is a fairly common mistake to identify a BSPT (tapered) as an NPT. Always remember that NPT threads have a 60° thread flank angle, and BSPT has a 55° angle (this can be verified with a thread gauge). Although BSP is a foreign thread, it isn’t actually metric. This is why it comes in imperial sizes: 1/8, 1/4, 1/2, 3/4, and so on.

BSP parallel threads commonly seal via a 30° chamfer on the male thread to a 30° recessed cone inside the female thread (swivel only). If it is a port application, an O-ring and washer or a bonded washer are needed to achieve a proper seal for parallel threads. For tapered BSP threads, a seal is acquired via thread wedging with additional support from thread dope or Teflon tape. As previously mentioned, it is possible for a male BSPT (tapered) to thread into a female BSPP (parallel), so long as the female thread is fixed and not swivel (this is because of the recessed cone seat).

http://www.tractorbynet.com/forums/hydraulics/188232-do-ccm-dpocv-fittings-require.html
__________________
J.J.
 
   / TnT Hydraulic connection??? BSPPM vs. NPTM
  • Thread Starter
#3  
The fitting in your hand with the cone, has a straight thread and mates with the recessed cone on the left of the picture...
That's the only thing I understood :confused2::confused2::confused2:

So the connectors that were shipped with it doesn't need to be used? They were sent with the toplink to make the ports BSPP?

I have plenty of 3/8" NPT for any connections that I need to make...

Here's a couple photos of the Lock Valve...
 
   / TnT Hydraulic connection??? BSPPM vs. NPTM #4  
An O-ring and washer or a bonded washer are needed to achieve a proper seal for BSPP threads. Did the supplier state that the ports were NPT or BSPP. Did they send the fittings specifically for the top link? How many fittings did they send with the unit?
 
   / TnT Hydraulic connection??? BSPPM vs. NPTM
  • Thread Starter
#5  
An O-ring and washer or a bonded washer are needed to achieve a proper seal for BSPP threads. Did the supplier state that the ports were NPT or BSPP. Did they send the fittings specifically for the top link? How many fittings did they send with the unit?
No "O" rings supplied. They said the ports were BSPP but wonder if these connectors were what they called the (end) port? They were sent with the toplink and they sent two...

I might just call them Monday to make sure... Thanks, J_J
 
   / TnT Hydraulic connection??? BSPPM vs. NPTM #7  
TEG,

Be aware the MAJOR difference between the BSPP & NPT is "One Thread Per Inch" in the 1/8, 1/4, 3/8, sizes.........(1/2 TPI in some larger sizes)

NPT vs. BSP Pipe | Pipe and Hose

Warning......Do not mix them up, the threads will trash-up if you do.....:thumbsup:
 
   / TnT Hydraulic connection??? BSPPM vs. NPTM #8  
Here is a long thread on this exact subject: Do CCM DPOCV Fittings Require O-rings? - TractorByNet.com

CCM for some reason thinks that a BSPP fitting does not need a O-ring...They are wrong.

Kenny,

Though I do agree with you on this, there's plenty of manufacturers that rely on the "Cutting Ring" or "Chamfer" machined into the sealing face to seal under high pressure.....

I like the washer/oring config for bspp.....
 
   / TnT Hydraulic connection??? BSPPM vs. NPTM
  • Thread Starter
#9  
Well, crap... I guess you say "B" is the correct way, but with a washer?

I'm back to calling Surplus center to find out WHY they sent the "...two 3/8" BSPPM to 3/8" NPTM connectors..." either to convert the NPT to the listed "Port: 3/8" BSPP" OR to convert the 3/8" BSPP to the NPT... which they do not mention... and I guess there is no way of telling since the difference is only 1 thread/inch??? (short of getting a guage)

I would have been better off, if they just use the plugs that were shown in the photo... but I know things change... I just don't know what they changed to???
 
   / TnT Hydraulic connection??? BSPPM vs. NPTM #10  
Teg, when I bought my HTL from the SC,I got the straight adapters they sold (separately at the time though) See pictures below. I then decided to got some 45* ones from DHH because they fit my situation better.

There are some up close pictures in my Picasa album: Picasa Web Albums - Ken Deckelman - HTL
 

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