Lochinvar 81 - 286 operation manual Near boiler piping components

6 Hydronic piping (continued)

Relief valve and temperature and pressure gauge installation

Basic steps are listed below to guide you through the installation of the relief valve and the temperature and pressure (T & P) gauge provided with the unit.

1.Install the tee with the 3/4 inch fitting positioned vertically and on the top as shown in FIG. 6-1.

2.Install the relief valve into the 3/4 inch fitting of the tee installed in Step 1 (FIG. 6-1).

3.Install a field provided close nipple and tee with the fitting positioned vertically on the top on the downstream side of the relief valve (see FIG. 6-1).

4.Install the temperature and pressure gauge provided with the unit into the top fitting of the tee (a bushing may be necessary) installed in Step 3 (FIG. 6-1).

Figure 6-1Relief Valve / T & P Installation

RELIEF VALVE

TEMPERATURE &

PRESSURE GAUGE

TEE W/FITTING ON TOP (FIELD PROVIDED)

CLOSE NIPPLE

(FIELD PROVIDED)

TEE WITH 3/4” FITTING ON TOP

CLOSE NIPPLE

Near boiler piping components

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 system 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.

Installation & Operation Manual

Knight 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. 6-3 on page 37 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. 6-3. 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 6-4 thru 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 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 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.

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.

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