#Liquid teflon tape free

Paste dope will spread and be pushed out of the way, and will not prevent the threads from properly engaging. Tape dope is too thick, and can actually prevent a good seal in straight thread joints. When working with fittings with straight threads, paste dope should always be used. Straight Threads Tapered Threadsįor pipes and fittings with tapered threads, I'll simply follow the guidelines mentioned above. This is especially true when working with 'black' pipe, since I want some corrosion protection in these joints. When working with fuel gas pipes of any kind, I always use a paste dope labeled for this use. I don't really have any particular reason for this, it's just the way I was taught. If I'm working with water pipe of any material larger than ~1', I'll always use paste dope. The paste dope will never harden or flake off, so I know the threads will be protected for a long time. The paste dope will give me the lube I need to get the pipes properly joined, while at the same time providing corrosion protection. Steel, Reactive Metalsīecause I don't want the threads to rust or react negatively, in this situation I'll use paste dope.

#Liquid teflon tape free

I'm just looking to lubricate the joint, so I can tighten it to create a leak free joint. In this situation I'll reach for PTFE tape, since it's not likely I'll require long term corrosion protection. Water Plastic, Soft Metals, Unreactive Metals The following are my personal guidelines. Which form of dope you choose is often based on who you learned from, personal preference, what's on hand, what type of pipe you're working with, etc. May be listed as MNPSF or FNPSF, for male and female threads respectively. NPSF like NPTF creates a mechanical seal due to the deformation of the threads, however, unlike NPTF NPSF threads are not tapered. May be listed as MNPS or FNPS, for male and female threads respectively. A thread seal agent is required, but should be selected differently due to the lack of taper. This type of thread is similar to NPT, except that the thread does not have a taper. May be listed as MNPTF or FNPTF, for male and female threads respectively. Since the seal is created by the threads themselves, a thread seal agent is not required (though may be used as a lubricant).

NPTF threads are designed so that when the threads are mated, they actually deform to create a mechanical seal. May be listed as MNPT or FNPT, for male and female threads respectively. However, this type of thread is tapered at a rate of 1/16 (3/4'/foot), which often allows a seal to be made without a sealing agent. Because of this, a thread seal agent may be required. This type of thread when mated, may contain slight gaps between the major and minor diameter of the threads. Thread Standards National Pipe Thread (NPT) The type of thread is determined by the tap or die used to create the threads, and should be labeled on the pipe or fitting. Whether dope is required at all, is dependent on the type of threads.