Справочник Пользователя для PVI Industries quickdraw pv500-26
QUICKDRAW
®
Boiler Water Heater
9
and cleaning frequency is established, initially inspect the tank every six months or more frequently if
higher scaling conditions are present.
Flush the tank at two or three-month intervals depending on water conditions in your location to help
prevent the accumulation of scale. To flush: turn off electrical disconnect switch to prevent the unit
from operating. Open the drain valve and allow water to flow through the tank until it runs clear. Close
the drain valve and turn the electrical switch back on.
higher scaling conditions are present.
Flush the tank at two or three-month intervals depending on water conditions in your location to help
prevent the accumulation of scale. To flush: turn off electrical disconnect switch to prevent the unit
from operating. Open the drain valve and allow water to flow through the tank until it runs clear. Close
the drain valve and turn the electrical switch back on.
WARNING: Since PVI cannot control the use of the water heater, water conditions, or
maintenance, the warranty on the water heater does not cover poor performance,
structural failure, or leaking due to an excessive accumulation of scale.
maintenance, the warranty on the water heater does not cover poor performance,
structural failure, or leaking due to an excessive accumulation of scale.
Cleaning the Heat Exchanger (refer to figure below)
1. Do not open until all pressure is removed, the unit is drained and the equipment surfaces cooled to
ambient temperature.
2. Heat exchangers subject to fouling or scaling should be cleaned periodically. A light sludge or scale
coating on the tube greatly reduces its effectiveness. A marked increase in pressure drop and/or
reduction in performance usually indicate cleaning is necessary.
reduction in performance usually indicate cleaning is necessary.
3. Tube bundle removal:
a. When practical, leave tube bundle attached to collar assembly and remove by unbolting collar
assembly from tank.
b. During bundle removal, the dead weight of bundle should never be supported on individual
tubes or contact any lined interior tank surface. Following removal, rest the bundle on the tube
sheet, support plates, or wood blocks cut to fit periphery of the bundle.
sheet, support plates, or wood blocks cut to fit periphery of the bundle.
c. Tube bundles may be raised using slings formed by bending light sheet metal into a “U” form
and attaching lifting lugs to the ends of the sheets. Baffles can be easily bent and damaged if
dragged over rough surfaces.
dragged over rough surfaces.
d. Before reinserting the tube bundle into the unit place the ring/tank gasket over the end of the
tube bundle and bring forward to the backside of the tube sheet.
CAUTION: When cleaning a tube bundle, tubes should not be hammered on with any metallic
tool and, in case it is necessary to use scrapers, care should be exercised that the scraper is
not sharp enough to cut the metal of the tubes.