Robertshaw Sight Glass 3/8ODF SG-3-S

The Robertshaw SG-3-S is a 3/8 inch ODF sight glass and moisture indicator installed in the liquid line of refrigeration and air conditioning systems.

A liquid line sight glass provides two pieces of information at a glance, and both are useful when interpreted correctly.

The first is the presence of bubbles. Refrigerant in the liquid line should be fully liquid, and bubbles indicate vapour is present. The most common cause is insufficient charge, but a restriction upstream, excessive liquid line pressure drop, or inadequate subcooling will produce the same appearance.

This is where sight glasses are most often misread. A clear sight glass does not confirm a correct charge, since a system can be overcharged and show clear liquid. Bubbles are a symptom requiring diagnosis rather than an instruction to add refrigerant, and charging until the bubbles clear is a well established route to an overcharged system.

The second is the moisture indicator, a chemical element that changes colour according to the moisture content of the refrigerant. It gives a direct indication of whether the system is dry, which is otherwise difficult to establish without laboratory analysis, and it is particularly useful after a repair or a burnout cleanup.

The indicator takes time to respond and should be read after the system has run.

Confirm connection size and type, pressure rating, and refrigerant compatibility before ordering.

Brand

Robertshaw

SKU

SG-3-S

Category

Sight Glasses

Weight

0.35 lbs

Dimensions

3.50" x 1.40" x 1.20"

Price

$40.00

Availability

In stock

Rating

4.6 / 5.0