Haws MK81A User Manual

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Model MK81A

Page 2 of 3

SUPPLY LINE: The minimum recommended line size is 1-1/4” IPS with 30-90 psi (2-6 ATM)
pressure. Where sediment or mineral content is a problem, an inlet filter is recommended.

PLUMBING CONNECTIONS: Inlet supply is female 1-1/4" NPT.

INSTALLATION: A minimum of 5.0 cubic feet of porous gravel fill around check valve. Flush
line before attaching valve.

TROUBLESHOOTING

PROBLEM

REPAIR CHECKLIST

1. Low flow/valve won't shut off.

Remove valve stem, check for debris.
Clean valve and flush line.

2. Valve won't shut off.

2. a. Check to see if stem seats on valve.

There should be clearance between
flag and top valve nut in closed
position. Adjust if necessary.

b. Check to see if stem packing is

excessive. Excessive pressure will not
allow spring to counter water pressure.
Adjust as needed.

c. High water pressure. Shim spring to

counter water pressure.

3. Valve leaks/won't shut off.

Remove valve stem, check O-ring and
rubber washer for damage. Replace as
needed using VRKMK81A repair kit.

For more information about Haws products, see our website:

www.hawsco.com

HAWS

and other trademarks used

in these materials are the exclusive property of Haws Corporation.