Near boiler piping components

6 Hydronic piping

1.	Boiler system piping:
	Boiler system piping MUST be sized per the pipe
	requirements listed in Table 6A. Reducing the pipe size
	can restrict the flow rate through the boiler, causing
	inadvertent high limit shutdowns and poor system
	performance. Flow rates are based on 20 feet of piping,
	4 - 90° elbows, and 2 - fully ported ball valves.
2.	Boiler circulating pump:
	A Grundfos UPS26-99F pump will be provided by the
	factory (for standard altitude models) as the boiler
	circulation pump based on 20 feet of piping, 4 - 90°
	elbows, and 2 - fully ported ball valves.
	Knight wall mount boilers are capable of controlling a
	variable speed	boiler circulator.	Variable	speed
	circulators MUST be sized to meet the specified
	minimum flow requirements listed in FIG. 6-2 on page 38
	at full speed.
3. Domestic hot water circulating pump:
	Field supplied. The pump MUST be sized to meet
	the specified minimum flow requirements listed in
	FIG. 6-2. Consult the indirect water heater operating
	guide to determine flow characteristics for the selected
	product used.
4.	Boiler isolation valves:
	Field supplied. Full port ball valves are required. Failure
	to use full port ball valves could result in a restricted flow
	rate through the boiler.
5.	Check valves:
	Field supplied. Check valves are recommended for
	installation as shown in FIG.’s 6-3 through 6-10. 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	ball valves	are

Installation & Operation Manual

11.Boiler purge valve:

Field supplied. The boiler purge valve is used to remove entrapped air from the heat exchanger during start-up.

12.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. Typically the sensor will be located far enough downstream to sense system diluted water temperature.

13.Indirect water heaters:

The Knight wall mount boiler may be piped to an indirect water heater to heat domestic hot water with the space heat transfer medium. As depicted in the piping diagrams on page 40 thru 47, there are two options when utilizing an indirect water heater.

A.The space heating piping will branch off to flow the space heat transfer medium through a single wall heat exchanger coil inside the indirect water heater.

B.The indirect water heater is connected to the system supply piping. A pump controlled by the Knight (wall mount) boiler’s control will regulate the flow of water through the indirect water heater. The indirect water heater’s temperature will be regulated by the Knight (wall mount) boiler’s control.

The Knight wall mount boiler is pre-configured to control the operation of the DHW pump with Domestic Hot Water Prioritization programming. The DHW programming is designed to control and balance the space heating demand by switching between DHW and space heating.

Lochinvar offers the Squire which is a series of indirect water heaters. The Squire features a stainless steel vessel with a single wall stainless steel heat exchanger.

	required. Failure to use full port ball 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.
8.	Unions:
	Field supplied. Recommended for unit serviceability.
9.	Temperature and pressure gauge:
	Factory supplied. The temperature and pressure gauge is

WARNING

The National Standard Plumbing Code, the National Plumbing Code of Canada and the Uniform Plumbing Code limit the pressure of the heat transfer fluid to less than the minimum working pressure of the potable water system up to 30 psi maximum. Also, the heat transfer fluid must be water or other non-toxic fluid having a toxicity of Class 1, as listed in Clinical Toxicology of Commercial Products, 5th Edition.

shipped loose. It is the responsibility of the contractor to

install the temperature and pressure gauge on the boiler

water outlet.

10. Pressure relief valve:

Factory supplied. The pressure relief valve is sized to

ASME specifications.

14.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.

6 Hydronic piping