1-1/2" NH/NST FDC Caps with Chain for Standpipe | Red Plastic Fire Department Connection Cover & Fire Hose Connection, Anti-Theft Dust Plug Sprinkler Caps, 2 Pack

◆Female 1-1/2" National Standard Thread (NST) for connecting to the hydrant ◆Inside diameter of 1.5" NST / NH adapter conforms to NFPA 1963 Standard for Fire Hose Connections 2014 Edition◆NH / NST: The most common thread type in use by fire departments today is NST or National Standard Thread. NST also goes by the initials NH or National Hose. It can even be referred to as NHT or National Hose Thread. But NST or NH is more common these days. NH = NST.◆NPSH: National Pipe Straight Hose (NPSH) or Iron Pipe Thread (IPT) has the same threads per inch (TPI) as National Pipe Tapered (NPT) but the thread does not taper. NPSH is a straight thread and seals by a gasket in the female coupling which allows for a swivel, just like NH / NST, which make both ideal for hose couplings. Warning - It will NOT thread into a female NPT pipe. For example, a male NPSH coupling will NOT thread into a female metal or pvc pipe.◆NPT: National Pipe Tapered is common in plumbing and some industrial uses. Sometimes referred to as pipe thread because PVC pipe and schedule 40 pipe are typically threaded in NPT. As its name implies this is a tapered thread so that the outside diameter of the male (ODM) gets smaller towards the end of the fitting and the inside diameter of the female narrows with depth. As the two fittings are threaded together the opposite tapers force thread friction and makes the seal without the use of a gasket.

• HEAVY-DUTY FDC CAPS: Designed for 1-1/2" NH/NST fire department connections, standpipe systems, fire hose connections, hydrants, and sprinkler fittings. Compatible with most standard fire protection equipment.
• ANTI-THEFT CHAIN DESIGN: Each fire sprinkler cap includes a durable metal chain that keeps the cap attached to the FDC connection, preventing loss, theft, or misplacement during inspections or emergencies.
• DUST & DEBRIS PROTECTION: Helps prevent dirt, and foreign materials from entering fire hose threads and standpipe connections, helping maintain reliable emergency access.
• DURABLE RED THERMOPLASTIC: Made from corrosion-resistant red thermoplastic material for indoor and outdoor fire protection systems. Lightweight, durable, and easy to install.
• 2 PACK FIRE DEPARTMENT CAPS: Includes two red FDC covers with chains for standpipe systems, hydrant connections, fire sprinkler systems, and commercial fire safety applications.