Brass 4 1/2" Female NH to 2 1/2" Male NH (Pin Lug) Inlet Size_5 Inch If you have a fire

If you have a fire department connection

It's usually installed on the inlet side (Suction Side) of a water pump to keep it from losing it's prime during the off cycle

This is the same water-handling accessories forestry wye valve found in the Defense Logistics Agency (DLA) Wildland Fire Equipment catalog or Fedmall

NPSH and NPT are more common in industrial applications

Brass 4 1/2" Female NH to 2 1/2" Male NH (Pin Lug) Inlet Size_5 Inch If you have a fireFemale to male adapters are used to bridge male to female hoses, pipes or valve fittings. Brass is commonly chosen for corrosion resistance, and is popular with chemical or salt water applications. Equivalent part number HA4525F WARNING: This product contains a chemical known to the State of California to cause birth defects or other reproductive harm. Do not use in connection with drinking water. Wash hands after handling. Brass Female to Male Adapter