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All Categories  > Trap Seal Primers and Water Hammer Arrestors  > M-500 Pressure Drop Activated Trap Seal Primers
M-500 Pressure Drop Activated Trap Seal Primers

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MIFAB® MR-500, M1-500 & M2-500 Series pressure drop activated brass trap seal primer, with inlet opening of 1/2" male N.P.T. and outlet opening of female 1/2" N.PT. Complete with four view holes and removable filter screen. Requires no adjustments and no air pre-charge. MIFAB's Series of pressure activated trap seal primers (MR-500, M1-500 and M2-500) can be connected to any cold water line and will be automatically activated when a valve or faucet, that is on the line, is opened.

A pressure drop of three p.s.i. will activate all of the trap seal primers. MIFAB's Series of trap seal primers can be disassembled in the field. Their unique design permits filter replacement without affecting the performance of the primer. The "O" ring seals are tested for reliability at a temperature range of -40 degrees to 450 degrees F. The M-500 Series of trap seal primers do not require adjustment. The operating range for all of MIFAB's Series of trap seal primers is 20 to 80 p.s.i.²

All three models are listed with I.A.P.M.O. and C.S.A. and are tested and certified to the A.S.S.E. Standard 1018 and are so marked. U.S. Patent # 6,152,164.

Shipping Weight

0.75 lbs.

Item Name

M-500 Pressure Drop Activated Trap Seal Primers


M-500 Pressure Drop Activated Trap Seal Primers

4 1/8"
Carton Qty.


Carton Weight
18.35 lbs.

1 1/4"

Dimensional Drawing
File Not Found

Compression Size
Outlet Size

1321 West 119th Street Chicago, IL 60643
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