Sight Glasses

Sight glasses, also known as flow sight glasses, are among the simplest yet most practical components used in industrial piping systems. Their primary function is to provide a visual indication of fluid flow, allowing operators to quickly verify whether the pipeline contains fluid and whether the system is operating as intended before carrying out inspection, maintenance, or commissioning procedures. Flow sight glasses are commonly installed on small branch pipelines, particularly in fire protection (firefighting) systems, where they form part of the traditional piping design used to verify that water is present and the system remains fully charged. Their simple construction incorporates a transparent inspection window, enabling maintenance personnel to visually confirm the presence, direction, and condition of the flowing medium without interrupting system operation. PGSAFE Flow Sight Glasses, distributed by PGTECH, are available in a comprehensive range of materials, sizes, pressure ratings, and connection types to suit a wide variety of industrial applications. In addition to standard models, PGTECH also offers custom-designed and manufactured sight glasses tailored to specific project requirements, including different body configurations, window designs, materials, and operating conditions. PGSAFE sight glasses are manufactured in accordance with internationally recognized quality and safety standards and are supported by certifications including ISO 9001, ISO 9001:2015, EJ/T 9001-2015 (Quality Management System for the Nuclear Industry), PED 2014/68/EU for pressure equipment, as well as European boiler equipment certifications. These certifications ensure reliable performance across a broad range of applications, including water systems, HVAC, fire protection, industrial process piping, power generation, and other demanding engineering environments.