Quality Level & Gauge Quality Series Q175 & Q170

 The Quality Series Q175 & Q170 Tubular Valves are the simplest and least costly devices that can assure accurate liquid level indication. Quality has two series available both with different designs. Both valves use transparent vertical tubes, where to lowest visible point connected to the tank or boiler at the lowest level of interest. The top of the glass is usually secured with another valve, but also may be open to the atmosphere if the tank is open. Isolation valves are placed above and below the gauge glass connections.

Quality Level & Gauge Quality Series Q175 & Q170

Automatic valves come with a corrosion-resistant ball checks. 316 stainless steel valves come with 316 stainless steel ball checks. These valves are designed for standard straights through flow with 1/2" or 3/4" vessel connections. These valves can be put together with highly durable Pyrex glass tube or high pressure tube of 5/8" or 3/4" diameter.  Guard rods and a round Plexiglas cover are available to protect the glass tube.

Automatic or non automatic for liquid level up to 500 PSI @ 100 F - Subject to elimination of glass tube


  • Glass tubing is 1” less than fixing centre
  • Protective guard rods are 1” less thank fixing centre

For fixing centres greater than 36”, Quality Gauge and Valve recommends a mid point support brace, which is also available in all materials.

A Self-adhesive vinyl transparent linear scale can be used on a tubular glass or around Plexiglas cover to indicate liquid level more accurately. The linear scale is available in both metric and imperial measurement.

Quality has slow closing valves and also valves with quick closing connections, where a one quarter turn of the valve spindle will allow the valve to change from the fully open to the fully closed position. Quality uses different valve spindles that are fitted with levers which allow chains to be attached in order to operate the valves from ground level. Quality drain valves or cocks may also be installed below the gauge glass for flushing to remove any solid material that may be collected.

Due to the constant supervision needed for many tanks and pressurized vessels, a broken tubular gauge glass can cause excessive amounts of liquids to escape. To prevent such occurrences, Quality equips the lower Tubular Valve with a protection shutoff. This device is the stainless steel ball which closes off fluid channel when the tubular glass is broken. When the tubular glass breaks, the unexpected rush of liquid through the valve will force the ball against the valve opening. With this type of safety shutoff the valve often requires more maintenance.  Another type of protection supplied by Quality is the Metal Shield. This device uses metal rods or shield to protect the tubular glass from breaking, it also protects the operator from debris should breakage occur.

The applications of tubular gauge glass are limited to lower pressure and temperatures. Many of the applications which are non-toxic and non-hazardous materials are used for this type of valve system. For tubular glass gauges exceeding 700 mm in length, Quality suggests using more valves to contain the operation.

Reference : qualitygauge.com