Match the fitting size to your existing pipe's nominal pipe size (NPS). For example, a 3/4" fitting connects to 3/4" NPT-threaded pipe. If you're branching to a smaller line, select a reducing tee that matches your run and branch diameters. When in doubt, measure the outer diameter of your pipe and consult an NPT size chart — typically a 3/4" NPT pipe has an OD of approximately 1.050" (26.7mm), and a 1" NPT pipe has an OD of approximately 1.315" (33.4mm).

These letter codes indicate the thread type on each of the three ports of the tee fitting. F = Female (internal/socket thread) and M = Male (external thread). The three letters correspond to Port 1 (run inlet), Port 2 (run outlet), and Port 3 (branch outlet), in that order. For example, FFM means two female run ports and one male branch port.

Brass NPT fittings generally handle working pressures up to 200 PSI for water and air at room temperature, and typically up to 250°F (121°C) for water service. Ratings can vary by size and wall thickness. Contact us to confirm the exact pressure and temperature rating for your specific size before use in critical applications.

Brass offers good corrosion resistance against water, air, and many mild chemicals, making it generally suitable for outdoor plumbing and irrigation use. However, brass is not recommended for highly acidic or alkaline environments, or for use with ammonia-based fluids. For harsh outdoor or marine environments, stainless steel fittings may be a better choice.

Yes. These fittings use NPT (National Pipe Taper) threads — the standard tapered thread system used in US residential and commercial plumbing, HVAC, and compressed air systems. They are compatible with standard NPT-threaded iron, steel, copper, and PVC pipe adapters. They are not compatible with BSP (British Standard Pipe) threads without an adapter.

Yes. NPT tapered threads rely on thread engagement plus a sealant to achieve a leak-free connection. Apply PTFE (Teflon) tape or a pipe thread sealant compound to all male threads before assembly. This is standard practice for all NPT fittings regardless of material, and skipping this step is the most common cause of leaks.

Brass fittings are commonly used in natural gas and propane systems in many regions. However, local codes vary — always verify with your local building code and a licensed plumber before using any fitting in a gas application. Contact us to confirm if a specific size is rated for gas service in your area.