Basic explanation of the different threads and their uses
- The hose shall be a single jacket construction with 100% spun polyester yarn.
- There shall be a minimum of 21.0 filler yarns per inch in the jacket.
- The thickness of the lining shall be 0.012" (305 µm) minimum and it shall be constructed of extruded T.P.U. elastomer.
- If required (optional), the outside jacket shall be treated with yellow ENCAP elastomer, which shall completely encapsulate the jacket fibers and not merely surface coat the jacket.
- The hose service temperature range shall be -60°F to 140°F (-51°C to 60°C).
- At 300 PSIG (2100 kPa), its elongation shall not exceed 2% of the initial hose length, it shall not warp more than 10 inches (25 cm) and should not rise from the test table.
- The hose shall not twist more than 5 turns per 50 ft (15,2 m) while at 300 PSIG (2100 kPa).
- Minimum service test pressure of 150 PSIG (1050 kPa).
- Minimum proof test pressure of 300 PSIG (2100 kPa).
- Minimum straight burst test pressure of 600 PSIG (4200 kPa).
- The hose while curved to a radius of 27" (69 cm) shall not burst at less than 600 PSIG (4200 kPa).
What is the difference between "NH", "NST", "NPSH", "IPT", and "NPT" threads? "NH", or National Hose, thread is the thread that has become the standard thread used in firefighting today (Cal Fire and Municipal Fire Departments). The threads specified in NFPA 1963 are "NH". This thread was previously known as "NST" or National Standard Thread. "NPSH", or National Pipe Straight Hose, is slightly smaller in diameter and has more threads per inch than the same nominal diameter "NH" thread. "NPSH" thread is sometimes referred to as "IPT", or Iron Pipe Thread and is commonly used in Forestry applications (USFS). "NH" and "NPSH" threads are not interchangeable. "NH" and "NPSH" threads are straight threads and require a gasket for sealing between mating threads. "NPT", or National Pipe Tapered, is the thread most commonly found in plumbing applications. Being tapered, the seal between mating threads is made by squeezing the threads together. No gasket is used. "NPT" and "NPSH" threads are similar in diameter and threads per inch.