Carrier PSD006-070, PSV Metal Hose Minimum Bend Radii, Typical Ground-Water Piping Installation

In all applications, the quality of the water circulated through the heat exchanger must fall within the ranges listed in the Water Quality Guidelines table. Consult a local water firm, independent testing facility, or local water authority for specific recommendations to maintain water quality within the pub- lished limits.

GROUND-LOOP APPLICATIONS — Temperatures be- tween 25 and 110 F and a cooling capacity of 2.25 to 3 gpm of flow per ton is recommended. In addition to complying with any applicable codes, consider the following for system piping:

•Limit piping materials to only polyethylene fusion in the buried sections of the loop.

•Do not use galvanized or steel fittings at any time due to corrosion.

•Avoid all plastic to metal threaded fittings due to the poten- tial to leak. Use a flange fitted substitute.

•Do not overtighten connections.

•Route piping to avoid service access areas to unit.

•Use pressure-temperature (P/T) plugs to measure flow of pressure drop.

INSTALLATION OF SUPPLY AND RETURN HOSE KIT — Follow these piping guidelines.

1.Install a drain valve at the base of each supply and return riser to facilitate system flushing.

2.Install shutoff/balancing valves and unions at each unit to permit unit removal for servicing.

3.Place strainers at the inlet of each system circulating pump.

4.Select the proper hose length to allow slack between con- nection points. Hoses may vary in length by +2% to –4% under pressure.

5.Refer to Table 3. Do not exceed the minimum bend radius for the hose selected. Exceeding the minimum bend radi- us may cause the hose to collapse, which reduces water flow rate. Install an angle adapter to avoid sharp bends in the hose when the radius falls below the required minimum.

NOTE: Piping must comply with all applicable codes.

Table 3 — Metal Hose Minimum Bend Radii

HOSE DIAMETER (in.)	MINIMUM BEND RADII (in.)
1/2	21/2
3/4	4
1	51/2

Insulation is not required on loop water piping except where the piping runs through unheated areas or outside the building or when the loop water temperature is below the minimum ex- pected dew point of the pipe ambient. Insulation is required if loop water temperature drops below the dew point.

IMPORTANT: Do not bend or kink supply lines or hoses.

Pipe joint compound is not necessary when Teflon threaded tape is pre-applied to hose assemblies or when flared-end connections are used. If pipe joint compound is preferred, use compound only in small amounts on the male pipe threads of the fitting adapters. Prevent sealant from reaching the flared surfaces of the joint.

NOTE: When anti-freeze is used in the loop, assure that it is compatible with Teflon tape or pipe joint compound employed.

Maximum allowable torque for brass fittings is 30 ft-lb. If a torque wrench is not available, tighten finger-tight plus one quarter turn. Tighten steel fittings as necessary.

Water	Flow
Control	Regulator
Valve	(field-installed
(field-installed	accessory)
accessory)

Pressure

Tank

Water Out

Water In

From Pump

Boiler

Drains (field-installed)

Shut-Off

Valve (field-installed accessory)

Strainer (field-installed accessory) (16 to 20 mesh recommended for filter sediment)

A50-7733

Fig. 13 — Typical Ground-Water Piping Installation

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