Allied Air Enterprises 4AC18LT manual Manifold Gauge Set, Liquid and Suction Line Service Valves

3.Connect the external equalizer line to the equalizer port on the suction line and tighten to 8 ft.lbs.

4.Strap the superheat sensing bulb to the suction header.

If installing an expansion valve on an indoor coil that previously used a fixed orifice, be sure to remove the existing fixed orifice. Failure to remove a fixed orifice when installing an expansion valve to the indoor coil will result in improper operation and damage to the system.

Manifold Gauge Set

Manifold guage sets used with systems charged with R410A refrigerant must be capable of handling the higher system operating pressures. The gauges should be rated for use with pressures 1 - 800 on the high side and a low side of 30” vacuum to 250 psi with dampened speed to 500 psi. Gauge hoses must be rated for use at up to 800 psi of pressure with a 4000 psi burst rating.

Liquid and Suction Line Service Valves

The liquid line and suction line service valves (See Figure

11)and service ports are used for leak teating, evacuation, charging, and checking charge.

Each valve is equipped with a service port which has a factory-installed Schrader valve. A service port cap protects the Schrader valve from contamination and serves as the primary leak seal.

To Access the Schrader Port:

1.Remove the service port cap with an adjustable wrench.

2.Connect gauge to the service port.

3.When testing is completed, replace service port cap. Tighten finger tight, then an additional 1/6 turn.

To Open Liquid or Suction Line Service Valve: Remove stem cap with an adjustable wrench.

Use service wrench with a hex-head extension to back the stem out counterclockwise as far as it will go. Use a 3/16” hex head extension for liquid line service valves and a 5/ 16” extension for suction line service valves.

Replace the stem cap. Tighten finger tight, then tighten an additional 1/6 turn.

To Close Liquid or Suction Line Service Valve:

1.Remove the stem cap with an adjustable wrench.

2.Use a service wrench with a hex-head extension to turn the stem clockwise to seat the valve. Tighten firmly.

3.Replace the stem cap. Tighten finger tight, then tighten an additional 1/6 turn.

Suction Line (Ball Type) Service Valve

Suction line (ball type) service valves function the same way as the other valves; the difference is in the construction (See Figure 12).

The ball valve is equipped with a service port with a factory- installed Schrader valve. A service port cap protects the Schrader valve from contamination and serves as the primary seal.

Leak Testing

After the line set has been connected to the indoor and outdoor units, the line set connections and indoor unit must be checked for leaks.

Figure 11

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