Plast-O-Matic Installation Tips for Sight Glasses

A Quick Guide to Proper Flow and Level Indicator Installation

Plast-O-Matic Sight Glass products play a crucial role in monitoring fluid flow and levels in piping systems, offering clear visibility for effective management. While installing flow and level indicators may seem straightforward, there are key factors to ensure they function correctly. Flow indicators can be installed either vertically or horizontally, providing flexibility in various applications, whereas level indicators must always be mounted vertically to maintain accurate readings. These sight glasses are designed for easy integration, featuring durable construction and user-friendly installation methods. By understanding these essential guidelines, users can maximize the performance and reliability of their Plast-O-Matic Sight Glass products, ensuring smooth operation in their industrial processes.

Threaded Sight Glasses

The Series GX single-wall and Series GY double-wall flow indicators are easily threaded into a piping system but should only be connected to plastic fittings. Wrap male threads with PTFE tape or an appropriate pipe sealant, tightening by hand, then give an additional one-quarter turn with a strap wrench. Over-tightening can stretch or deform the plastic, leading to potential rupture. Avoid using pipe wrenches, locking pliers, or vise grips, as they can stress the plastic. Also, never connect directly to metal pipes—always use plastic nipples to prevent cutting into the plastic and causing a future rupture.

Flange Installation

The Series GYW wafer design flow indicators are designed to fit between two smooth-faced companion flanges, which can be either metal or plastic. No flange gaskets are needed, as the flow indicators come with two O-rings for sealing. Ensure the flanges are properly aligned before tightening. Gradually tighten the flange bolts, alternating between opposite bolts, similar to tightening lug nuts. The final 1/16″ of tightening should be done with a torque wrench set to 10-15 foot pounds to properly seal the O-rings without over-stressing the assembly. While these flow indicators do not have a specific inlet or outlet, if using streamers or fluttering devices, make sure to install them so that fluid flow directs the streamers into the viewing area for proper operation.

Level Indicators

Series GL level indicators are typically mounted vertically on the outside of a tank and come with female threads. Similar to the GX and GY models, installation should start by wrapping male threads with PTFE tape and tightening by hand, followed by an additional 1/4 turn using a strap wrench. If connecting to metal piping, always use plastic nipples between the fittings.

A useful tip is to connect the top and bottom of the level indicators with true-union ball valves. This allows for easy removal of the indicators for cleaning or inspection while maintaining liquid levels in the tank. Although the Series GL is available in 1 or 2-foot lengths, they can be installed on taller tanks by staggering them to maintain a continuous visual indication, avoiding any dead spots. Avoid connecting them directly with pipe nipples, as this creates dead spots and an unstable assembly.

A Clear View on Effective Solutions

Keep in mind that when the liquid in the piping system is turbulent, flow is easy to see without the need for fluttering devices. However, for clear or opaque liquids that are calm and lack air bubbles, it can be harder to detect flow. In such cases, a fluttering device inside the cylinder will help indicate liquid movement. Once installed correctly, Plast-O-Matic flow and level indicators operate automatically and require minimal maintenance.

Plast-O-Matic Sight Glass products are vital for monitoring fluid flow in piping systems, providing clear visibility and measurement capabilities. Offered in various configurations, including single-wall and double-wall designs, these sight glasses cater to a wide range of applications. Their straightforward installation — featuring threaded connections for plastic fittings and O-ring seals for flange designs — ensures seamless integration while reducing the risk of leaks or ruptures. With customization options available, Plast-O-Matic Sight Glasses enhance operational efficiency, making them essential for effective fluid management in industrial environments.

As with all Plast-O-Matic products, Sight Glasses can be customized in various ways or fully redesigned to meet specific application needs. For more information about Sight Glass products, click below.

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