Pressure activated trap primer and water hammer combination

A water hammer arrestor and trap seal primer, comprising:

• a side inlet connectable to system plumbing, a bottom outlet connectable to a plumbing drain trap, said bottom outlet including an integral air gap, and an expansion chamber located above said side inlet and said bottom outlet;
• a distributor interposed between, and in fluid communication with, each of said side inlet, said bottom outlet and said expansion chamber, said distributor including an internal channel and one or more external channels;
• a check piston within said distributor internal channel disposed between said side inlet and said bottom outlet, said check piston including a one-way seal allowing flow from said internal channel to said external channels;
• wherein, when system plumbing pressure exceeds gas pressure in said expansion chamber, said check piston seats against said bottom outlet, and said one-way seal permits water flow from said internal channel to said expansion chamber via said external channels, thereby reducing pressure in said system plumbing by trapping a volume of water;
• and further wherein, when system plumbing pressure decreases to less than expansion chamber gas pressure, said check piston seats against said internal channel, thereby porting said received water volume exclusively to said bottom outlet via said external channels.

A water hammer arrestor and trap seal primer, comprising:

• an inlet connectable to a plumbing system;
• an expansion chamber above said inlet;
• an outlet below said inlet, said outlet connectable to a plumbing system drain trap, and said outlet including an integral air gap;
• first check valve means between said inlet and expansion chamber permitting rapid inflow of water due to water pressure event, but preventing flow from expansion chamber to inlet;
• second check valve means between said expansion chamber and said outlet;
• such that when fluid pressure at said inlet rises above gas pressure in said expansion chamber as in a water hammer event, said first check valve means allows water inflow into said expansion chamber, thereby reducing plumbing system pressure caused by a water hammer event, and further wherein, said second check valve means prevents flow from said expansion chamber to said outlet;
• and, such that when fluid pressure at said inlet drops below gas pressure, said first check valve means prevents return flow from said expansion chamber into said inlet and said second check valve means permits water flow from said expansion chamber to said outlet, thereby directing water received during a water hammer event to drain and preventing a reflected water hammer event.

A water hammer arrestor and drain trap primer valve, comprising:

• A hollow pipe including an inner wall, a closed end, a discharging end, and inlet;
• An outlet port connected to said discharging end and attachable to plumbing tubing;
• An inlet port connected to said inlet and attachable to plumbing tubing;
• An insert plug within said pipe positioned at said discharging end and at said inlet, said insert plug substantially tubular and having a circular cross-section with an eccentric centerline in relation to said hollow pipe so as to allow fluid flow between said insert plug and said hollow pipe inner wall, and said insert plug further including a longitudinal cylindrical bore and a latitudinal threaded through bore;
• A port bolt within a portion of said insert plug and a portion of said inlet port, said port bolt substantially tubular and having a longitudinal cylindrical bore and a latitudinal through bore distributor aligned with the insert plug longitudinal cylindrical bore;
• and
• A check piston within said pipe and slidingly engageable with said insert plug and said outlet port wherein said check piston engages slidably responsive to water pressure changes at said inlet port.