Raypak 503-2003 manual Three-WayValves, Domestic Hot Water, Potable Water and Space Heating

Three-Way Valves

Three-way valves intended to regulate system water temperatures by reducing flow in the boiler should not be used. Raypak heaters are high-recovery, low-mass heaters which are not subject to thermal shock. See Fig. 16 and instructions on page 17 for adjusting the manual bypass.

Domestic Hot Water

When designing the water piping system for domestic hot water applications, water hardness should be con- sidered. Table G indicates the suggested flow rates for soft, medium and hard water. Water hardness is ex- pressed in grains per gallon.

SYSTEM

SUPPLY

SYSTEM

RETURN

Fig. 14: Single Domestic Hot Water Heater and Storage

Tank

NOTE: If local codes require a vacuum relief valve, acquire one locally and install per valve manufacturer’s instructions.

Potable Water and Space Heating

CAUTION: When this heater is used for both potable water and space heating, observe the following to ensure proper operation.

1.All piping materials and components connected to the water heater for the space heating application shall be suitable for use with potable water.

2.Toxic chemicals, such as used for boiler treatment, shall not be introduced into the potable water used for space heating.

3.If the heater will be used to supply potable water, it shall not be connected to any heating system or components previously used with a non-potable water heating appliance.

4.When the system requires water for space heating at temperatures higher than 140°F (60°C), a means such as a mixing valve shall be installed to temper the water in order to reduce scald hazard potential.

Pool Heating

When a boiler or water heater is used in a pool heat- ing application, ensure that all the following installation requirements are met.

Model	Soft (0-4 grains per gallon)					Medium (5-15 grains per gallon)					Hard* (16-25 grains per gallon)
No.	T	gpm	P	MTS	SHL	T	gpm	P	MTS	SHL	T	gpm	P	MTS	SHL
503	17	50	3.6	2	5.9	17	50	3.6	2	5.9	9	95	10.4	2	18.1
753	26	50	4.0	2	6.3	20	65	6.4	2	10.2	13	100	13.8	2	22.2
1003	30	58	6.0	2-1/2	7.2	20	87	12.0	2-1/2	14.4	15	113	18.7	2-1/2	22.6
1253	30	73	10.4	2-1/2	12.1	20	109	21.0	2-1/2	24.6	19	113	22.3	2-1/2	26.3
1503	30	87	16.0	2-1/2	18.5	23	113	25.7	2-1/2	29.6	23	113	25.7	2-1/2	29.6
1753	30	102	22.7	2-1/2	26.0	27	113	27.4	2-1/2	31.3	27	113	27.4	2-1/2	31.3
2003	30	116	32.0	2-1/2	36.1	30	116	32.0	2-1/2	36.1	30	116	32.0	2-1/2	36.1
∆T = Temperature		rise,	°F
∆P = Pressure drop through heat exchanger, ft
SHL = System head loss, ft (based on heater and tank placed no more than 5 ft apart and equivalent length of 50 eq. ft. of tubing)
gpm = Gallons per minute, flow rate
MTS = Minimum tubing size
*Must utilize optional cupro-nickel tubes. If over 25 grains per gallon, a water softener/treatment system must be utilized.
Caution: For scale free operation with "Hard Water" (16-25 grains per gallon of total hardness), the operating control must NOT be set
higher than 130 F. For higher than 130 F operation, a water softener/treatment system must be utilized.
				Table G: Domestic Water Heater Flow Rate Requirements
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