Raypak 503-2003 manual Temperature & Pressure Gauge, Cold Water Run

SECTION C: Installation

matic valve system, such as a three-way proportional valve or a modulating two-way valve to control the bypass, should be utilized.

temperature would be 130ºF. An injector pump ar- rangement may also be utilized to keep the heater loop at or above 120ºF (49ºC). An injector pump approach has the added value of being able to adjust to changes in the system water coming back to the heater take-off.

Fig. 7: Cold Water Start

Cold Water Run

Cold water run differs from cold water start in that the system water entering the heater remains below 120ºF (49ºC) continuously. Typically, this is the case in swimming pool heating and water source heat pump applications as well as some others. If the system water is kept in a narrow temperature range of no more than 10ºF, a permanent manual bypass can be employed and manually adjusted to achieve an inlet temperature of 120ºF (49ºC) or higher as adjusted at the minimum temperature in this narrow temperature range (i.e. Range 75ºF – 85ºF – adjust bypass with temperature at 75ºF) so that when temperature is 85ºF, minimum inlet

Fig. 8: Cold Water Run

Temperature & Pressure Gauge

The temperature and pressure gauge is shipped loose for field installation in the outlet piping.

Model	20°F∆T		30°F∆T		40°F∆T			Min. Flow				Max Flow
No.	gpm	∆P (ft)	gpm	∆P (ft)	gpm	∆P (ft)	gpm		∆P (ft)	∆T	gpm		∆P (ft)	∆T
503	44	2.8	29	1.4	N/A	N/A	25		1.1	35	100		11.3	9
753	65	6.4	44	3.1	33	1.9	33		1.9	40	100		13.8	13
1003	87	12.0	58	6.0	43	3.7	43		3.7	40	113		18.6	15
1252	109	20.9	73	10.2	54	6.2	54		6.2	40	113		22.2	19
1503	N/A	N/A	87	16.0	65	9.5	65		9.5	40	113		25.5	23
1753	N/A	N/A	102	22.5	76	13.4	76		13.4	40	113		27.2	27
2003	N/A	N/A	116	31.9	87	18.9	87		18.9	40	116		32.0	30

Notes: 1. Basis for minimum flow is ∆T . Basis for maximum flow is gpm.

Table F: Heater Rates of Flow and Pressure Drops

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