Repair manual

WATER QUALITY REQUIREMENTS — 2-PROBE
TYPE STEAM GENERATOR PROTECTION
AND MAINTENANCE
A steam generator, or boiler, unlike other types of water-using
kitchen equipment, distills the water in order to make steam.
Nearly all feed-water sources contain dissolved minerals in
varying degrees of concentration. As this water is boiled, pure
steam rises from its surface, upward to the cooking
compartments), leaving minerals behind, that can become harmful
to the steam generator. If minerals are allowed to accumulate
inside the steam generator, they will solidify as a scale. Then,
malfunctioning will occur, and serious equipment damage may
result.
The use of good quality generator feed water is the responsibility
of the owner/user. The use of poor quality feed water could void
equipment warranties. The minimum treatment required in most
areas is water softening, although local water conditions may
require more intensive pretreatment than simply a water softener.
Scale problems occur when feed water is high in hardness, total
dissolved solids, silica and alkalinity. Water softening will only
reduce the water's hardness, which is the presence of dissolved
salts of magnesium and calcium. Water softening will not affect
the multitude of other minerals found in most water supplies.
Because generator scale is the result of the precipitation of many
minerals, the best property to control, for generator feed water, is
total dissolved solids, not just hardness.
The recommended minimum water quality standards. whether
untreated or pre-treated, based upon 8 hours of use per day. and a
Daily Blowdown, are as follows:
INSTRUCTIONS FOR CHEMICALLY DESCALING
2-PROBE TYPE STEAM GENERATORS
WARNING: Steam under pressure may cause serious
injury and bodily harm when it is accidentally or
carelessly released. Improper handling of acid could
cause serious, permanent injury. Therefore, service of
the steam generator should only be performed by
trained and experienced personnel, thoroughly familiar
with servicing generators.
There are a number of commercial descaling chemicals available,
produced by various manufacturers. Those utilizing a sulfamic acid
base, which can be identified by its powdered form. are safe and
compatible with our food preparation equipment It is imperative
that the acid used for descaling be FDA approved, for use in food
preparation equipment Various manufacturers may include
additional chemicals to increase potency, and therefore.
instructions for a specific brand should be followed carefully. If
instructions are not provided with the deliming chemical you
purchase, the following general guidelines may be followed.
WARNING: Exercise care when handling acid. Avoid
contact with skin, eyes, or clothing. Wear safety glasses
or face shield, along with rubber gloves and rubber
apron. In case of exposure to clothing, remove clothing
and flush with water. In case of exposure to skin or eyes,
flush with water for 15 minutes and get immediate
medical attention. Do not take internally. Keep out of
the reach of children.
TOTAL DISSOLVED SOLIDS less than 60 parts per million
TOTAL ALKALINITY less than 27 parts per million
SILICA less than 13 parts per million
pH FACTOR greater man 7.5
Consult the state department of water or a local water treatment
specialist for an on-the-premises water analysis and for
recommendations concerning steam generator teed water treatment
(if required), in order to remove or reduce harmful concentrations
of minerals.
If the recommended water quality requirements are met without
supplemental treatment or if treatment is applied. resulting in feed
water quality meeting the prescribed standards, the steam generator
will need to be blown down only once every 8 hours. In addition,
the inside of the generator requires an inspection (for excessive
lime accumulation) only once every six months. Chemically
descale the generator as required.
If a pre-treatment unit cannot be installed, and the recommended
water quality requirements are not met the following procedures
should be followed, in order to achieve maximum steam generator
service life. The steam generator should be blown down after each
4-6 hours of use, have the steam generator inspected, inside and
outside, by a qualified technician every three months. If the inside
of the generator is heavily coated with scale, have it chemically
descaled by a qualified service technician.
Be sure the generator has been drained, de-pressurized. and is cool.
Open the hand hole access plate on the front of the generator and
place approximately 8-10 pounds of sulfamic acid inside the
generator. Put a new hand hole gasket on the hand hole plate, and
replace the hand hole plate, tightening the bar and nut assembly to
a maximum of 15 foot pounds torque. The generator must be com-
pletely filled with water (fill the generator beyond its normal,
automatic fill point of 2/3 up in the sight gauge). This can be
accomplished by temporarily disconnecting the wire from the water
level probe at the water level control board. The board is marked
"HI" at this connection point Turn the main on-off rocker switch to
the "ON" position, then close the manual water feed valve when
the generator is completely filled. Leave the on-off rocker switch in
the "on" position to prevent the generator from automatically
draining. Reconnect the probe wire to the "HI" terminal of the
water level control board. Let the solution stand for several hours,
then flush with water. Rinse with a solution of bicarbonate of soda
to neutralize any acid residue, and again, flush with water. Be sure
to reconnect the wire to the water level control board and to open
the manual water teed valve.
CAUTION: Never tighten the hand hole plate nut when
the steam generator is in use, hot, or otherwise
pressurized. Never tighten nut over 15 toot-pounds
torque. Overtightening may cause uneven stress, which
may result in the weakening and possible breakage of
the plate.