Crestron electronic 3.5, 2.5, 1.5 service manual Near boiler piping components

Installation & Operation Manual

5 Hydronic piping

Near boiler piping components

1.	Boiler piping:
	Boiler system piping should be sized per the pipe
	requirements listed in Tables 5A and 5C.
2.	Boiler circulating pump:
	Field supplied. When using Primary/Secondary piping the
	boiler circulating pump should be sized per Table 5A.
3.	Hot Water Generator circulating pump:
	Field supplied. When installed in a Primary/Secondary
	arrangement, the Crest requires an additional pump for

NOTICE	A system supply sensor (factory supplied)
	MUST BE installed with Primary/Secondary
	systems for proper boiler operation.

10.Y-Strainer:

Field supplied. A Y-strainer or equivalent multipurpose strainer is recommended at the inlet of the heat exchanger to remove system particles from older hydronic systems and protect newer systems.

the Hot Water Generator Loop. The pump should

be sized per Table 5A. Consult the indirect water

heater operating guide to determine flow characteristics

for the selected product used. The pump’s total flow and

heat requirements are the sum of the boiler and the indirect

water heater.

4. Boiler isolation valves:

Field supplied. Full port valves are required. Failure

to use full port valves could result in a restricted flow

rate through the boiler.

￿CAUTION

NOTICE

The maximum allowable water flow rate through a single Crest boiler is 350 GPM. Exceeding this flow rate will result in damage to the heat exchanger and/or piping.

Reference Table 5B1 for the minimum recommended flow rate through a single Crest boiler at full fire to maintain a 80°F temperature rise. Reference Table 5B2 for the absolute minimum flow rate through a single Crest boiler.

5.	Check valves:
	Field supplied. Check valves are required for
	installation as shown in FIG.’s 5-2 and 5-3. Failure to
	install check valves could result in a reverse flow
	condition during pump(s) off cycle.
6.	Domestic indirect hot water isolation valves:
	Field supplied. Full port valves are required. Failure to use
	full port valves could result in a restricted flow rate through
	the boiler.
7.	Anti-scald mixing valve:
	Field supplied.	An anti-scald mixing valve is
	recommended when storing domestic hot water above
	115°F (46°C).
8.	Pressure relief valve:
	Factory supplied. The pressure relief valve is sized to
	ASME specifications.
9.	System temperature sensor:
	Lochinvar supplies	a	system	temperature sensor.
	The sensor is to be installed in the heating loop
	downstream from the boiler hot water piping and
	heating loop junction.		The	sensor should be
	located far enough downstream to sense system diluted
	water temperature.

Table 5B1 Minimum Flow Rate with the Boiler at Full Fire

TEMPERATURE RISE APPLICATIONS

MODEL	FLOW RATE (GPM)
FB(N,L)1500	35
FB(N,L)2000	46
FB(N,L)2500	58
FB(N,L)3000	70
FB(N,L)3500	81

[Based on 80°F Temperature Rise]

Table 5B2 Absolute Minimum Flow Rate

ABSOLUTE MINIMUM FLOW RATE

MODEL	FLOW RATE (GPM)
FB(N,L)1500	25
FB(N,L)2000	25
FB(N,L)2500	25
FB(N,L)3000	25
FB(N,L)3500	45

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