Xylem MM 802F User Manual

Model TC-4 Test-N-Check®Valves For Hot Water Boilers

Does in minutes what used to take hours.

INSTRUCTION MANUAL

MM-802F

Applications: For isolation of equalizing lines during low water cut-off testing.

OPERATION

Maximum Operating Pressure: 160 psi (11 kg/cm2) Maximum Operating Temperature: 250˚F (121˚C)

UTIO

NIN

• Before using this product read and understand instructions.

• Save these instructions for future reference.

• All work must be performed by qualified personnel trained in the proper application, installation, and maintenance of plumbing, steam, and electrical equipment and/or systems in accordance with all applicable codes and ordinances.

• To prevent serious burns, the boiler must be cooled to 80˚F (27˚C) and the pressure must be 0 psi (0 bar) before servicing.

TC-U Upper Valve TC-L Lower Valve

WARNING

• To prevent serious personal injury from steam blow-down, connect a drain pipe to the control opening to avoid exposure to steam discharge.

California Proposition 65 warning! This product contains chemicals known to the

•

state of California to cause cancer and birth defects or other reproductive harm. Previous controls should never be installed on a new system. Always install new

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controls on a new boiler or system.

Failure to follow this warning could cause property damage, personal inj ury or death.

CAUTION:

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A more frequent replacement interval may be necessary based on the condition of the unit at time of inspection. McDonnell Miller s warranty is one (1) year from date of installation or two (2) years from the date of manufacture.

Simplify Testing of Low Water Cut-offs on Hot Water Boilers

TEST-N-CHECK®VALVES

IMPORTANT:

• When using tape sealant or thread joint compound on pipe or fittings with external threads follow manufacturer’s instructions. Do not use tape sealant or thread joint compound on first thread.

To prevent serious personal injury from steam pipe blow down, connect a drain pipe to the control opening to avoid exposure to steam discharge.

If vacuum breaker stem is accidentally depressed, hot water could be discharged causing burns.

Failure to follow this caution could cause personal injury.

CAUTION

TEST-N-CHECK VALVES SIMPLIFY TESTING OF LOW WATER CUT-OFFS ON HOT WATER BOILERS Good operating practice requires installation of a low water cut-off on a hot water boiler and that it be checked regularly to make certain the control will function properly in the event of a low water condition. Boiler owners and installers need a quick and efficient way to test a low water cut-off on a hot water boiler. Simply opening a blow-off valve below the float chamber may not serve as a valid test and is excessively wasteful of boiler water and fuel. The water level in the float chamber, and the float, must drop far enough to start the control through its cycle of operation. However, water flowing in through the equalizing piping may replenish the level in the float chamber fast enough to delay the necessary float drop, or prevent it altogether. McDONNELL & MILLER Test-N-Check Valves have been specially designed for such installations. In normal operation, they allow free circulation of water through the equalizing piping and float chamber. But any sudden onrush of water, such as caused by opening the blowoff, snaps shut a damper in each valve to restrict flow to the float chamber. Water level in the float chamber falls quickly to start the control through its operating cycle, with a minimum loss of boiler water. When blow-off is closed, dampers return to normally open position. McDONNELL & MILLER Test-N-Check Valves simply replace the crosses above and below the control in the equalizing lines. Valves have the same dimensions as standard crosses and nipple in the horizontal leg, and allow normal rod clean-out of pipe in both directions. Connections are 1" NPT female tappings. Upper and lower valves are identical, except that the upper valve has vacuum breaker built in to allow for rapid evacuation of the float chamber. They are furnished in sets-one upper and one lower valve, to equip one equalizing line. They can be used with all McDONNELL & MILLER Low Water Cut-Offs for hot

water boilers.

LWCO

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