Malleable Iron Fittings - Galvanized

Q. "How are Tee fittings sized?"
A. Tees are sized by using the run (straight through portion) of the tee first and then the side outlet. The largest size of the run is named first and then the smaller size of the run and then the side outlet size. Example: 3/4" x 1/2" x 1/2". When only two sizes are provided for the Tee description the run size is listed first and then the side outlet. This means the run has the same size on both ends. Example: 3/4" x 1/2". A Tee that is 1/2" x 3/4" is often referred to as a Bull Head Tee because the run is smaller sized than the side outlet. This way of sizing Tees is the same for all Tees in plumbing no matter what material (PVC, copper, ABS, cast-iron, etc.) is being used.

Q. "I tightened my threaded nipple into my female threaded fitting, but it won't thread all the way in. Some of the threads are still showing. Shouldn't it thread all the way in?"
A. No, tapered threads should not thread all the way in. Tapered pipe threaded nipples are not designed to thread all the way into the female thread fittings. Tapered pipe threads are designed to get tighter as they are joined, until they are forced to stop because of the taper, or pressing the threads together to form the seal. Pipe threading compounds and PTFE tape are used to lubricate and fill in any imperfections in the threads to help prevent leaks. Once tightened by hand and then with a wrench there should usually still be 2-3 threads showing. If you try to force the threads beyond the normal tightening proceedure, then you could possibly split the female fitting. Generally and ideally speaking, you should be able to hand tighten tapered pipe threads 3 turns and then tighten them with a wrench 3 turns and then there should be 3 threads showing.

Q. "Will IPS-sized fittings work with NPT pipe thread?"
A. Yes. The abbreviation IPS normally refers to iron pipe size. When we use the term 'IPS-sized' we are referring to pipes with NPT threads. NPT is the abbreviation for National Pipe Thread Tapered which is the thread standard used in the United States for galvanized, black, brass, stainless steel, PVC, ABS or other materials to connect pipes and fittings in plumbing. We offer more detailed information about NPT pipe threads here.

Q. "What does Class 150 mean?"
A. All types of pipe and fittings are tested to ensure they meet specific temperature and pressure requirements. Class 150 is one of the ratings given to galvanized malleable iron pipe fittings as determined by the ASME (American Society of Mechanical Engineers). ASME B16.3-2006 is the standard used to test malleable iron threaded fittings to make sure they meet the proper pressure and temperature ratings. A Class 150 rating means these fittings have been tested and approved for a maximum pressure of 300 PSI at 150°F. The black and galvanized fittings we sell are also UL (Underwriters Laboratories) and FM (Factory Mutual Insurance Company) approved. FM has an independent testing facility where products are tested to make sure they meet the highest level of standards for safety and property loss prevention.