Fuel Pump Fittings

T

tommyleea

Senior Member
1/4 x 18 NTSF opening in my fuel pump. I want a fitting, that will screw into that opening, with a 5/16 hose barb. I cannot locate a fitting with NTSF designation. Only fittings I find are standard pipe thread. I guess the NTSF is straight thread fuel. Does anyone know if the standard pipe thread fitting will work? Will it seal properly? I am not familiar with NTSF, but maybe I have encountered them for years, and just didn't know it. Thanks..Y Block
 
Are you sure it's not NPSF (National-Pipe-Straight-Fuel). Straight thread fittings require either a sealing o-ring or a soft metal sealing washer. Most of the old Ford stuff is NPT but there are exceptions.

NPTF is the most common for fuel line & fitting connections. What type of pump do you have?
 
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rotorwrench said:
Are you sure it's not NPSF (National-Pipe-Straight-Fuel). Straight thread fittings require either a sealing o-ring or a soft metal sealing washer. Most of the old Ford stuff is NPT but there are exceptions.

NPTF is the most common for fuel line & fitting connections. What type of pump do you have?
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Correct..NPSF..It is a Delphi AMF 0063..I was going to try a carb inlet fitting, but I would still need the hose fitting. NPSF doesn't seem to be a hardware store option. Thanks
 
Yes, as others said, that is a taper thread. A fitting to go directly to a hose barb is also a readily available item. Try a hardware store and look in the house plumbing section. I bet you will find one.
 
dmsfrr said:
Is there a specialty store near you that deals in replacement pneumatic and hydraulic hoses?
They may have what you need.
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I will check that out. There was one in town, but I don't know if it is still in business. Thanks

34pickup said:
Fastenal has a bodacious amount of brass fittings.
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We do have Fastenal.. I will check that out. Thanks

packrat5 said:
Yes, as others said, that is a taper thread. A fitting to go directly to a hose barb is also a readily available item. Try a hardware store and look in the house plumbing section. I bet you will find one.
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Rotorwrench corrected me..It is a straight thread for fuel. Thanks
 
What are others using for the fuel pump fittings? This is for a Y Block 272. I must be confusing the issue. Do I just need to use pipe fittings? I guess I just never dealt with or i am not familiar with the NPSF designation. Thanks
 
Okay, so, that is a brass fitting and it is a NPT thread (tapered pipe thread). At the very most, you might be able to get away with using a new fitting that you put on your pump ONE MORE TIME without leaks. Problem is, you want to get them pretty tight, and in doing so, you crush the pipe in the threaded hole.
Best practice is to use a brand new brass fitting every time you change the fuel pump. Last time I did, I went and picked up three new fittings from the hardware store. Once you get that fitting tight in the threaded hole of the fuel pump, HOLD the hex head on that fitting with an open-end wrench while tightening your new flexible inlet hose into that fitting. The other end of that flexible hose has a revolving fitting on it so the hose can remain stationary.
 
There is a taper thread pipe fitting, and a straight thread. Straight thread was not really ever used in the automotive field, except for the plumbing on those old Thermacter emission systems. I think that was done so no one would "fiddle" with them.
 
regardless of which pump you have, they use the NPT (tapered) National pipe thread fitting.
You won't see much straight pipe thread used in plumbing these days. Back in the late 1800's and early 1900's, straight pipe thread was used extensively in the assembly of factory machinery and smelting furnaces, etc. I'd be surprised if you could find any in stock in the local hardware store.
Typically, straight pipe thread was used in applications to assemble large pieces of equipment using two locknuts (one on each side of the flat plate of the machine being assembled).
 
Daves55Sedan said:
regardless of which pump you have, they use the NPT (tapered) National pipe thread fitting.
You won't see much straight pipe thread used in plumbing these days. Back in the late 1800's and early 1900's, straight pipe thread was used extensively in the assembly of factory machinery and smelting furnaces, etc. I'd be surprised if you could find any in stock in the local hardware store.
Typically, straight pipe thread was used in applications to assemble large pieces of equipment using two locknuts (one on each side of the flat plate of the machine being assembled).
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Maybe it is just a misnomer in the description of the fuel pump, and it is actually tapered pipe thread? I think I will go in that direction..Thanks..
 
Straight pipe thread is a lot more common in aviation than it is in the automotive world. We keep a lot of o-rings around for the different helicopters. Boss types are common for fuel, oil, and hydraulic fittings. Some are custom fittings with either aluminum or copper seal washers. We use lock-o-seals in some cases. They are a combination of a metal washer and an synthetic rubber o-ring.
 
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