Control Valve Trim Styles and Flow Characteristics

Hi-Flow™ Valve Cutaway

Hi-Flow™ Control Valves vary the flow in a system by throttling the valve plug in and out of the valve seat. The corresponding flow rate through the valve is based on the valve plug and seat type, which is part of the valve trim. Dwyer Instruments, Inc. offers several flow characteristics, needle plugs, and restricted trim options for the Hi-Flow™ Control Valve series.

There are two types of inherent flow characteristic trim styles available in the Hi-Flow™ product line: Linear and Equal percentage. Continue reading “Control Valve Trim Styles and Flow Characteristics”

Flow Measurement with Orifice Plates

Dwyer Instruments, Inc. offers many types of flow measuring products including orifice plates, which are used as a flow sensing element with a differential pressure monitor.

Orifice Plates

Orifice plates are a primary flow element, detecting the flow of a fluid passing through the plate by sensing the pressure drop across the plate. When a fluid flows through a restriction in a pipe, it creates a pressure difference between upstream and downstream of the restriction. This pressure difference is proportional to flow rate according to Bernoulli’s principal, similar to a Pitot tube.  Orifice plates are commonly used as they are simple to use, low cost, work with gases or liquids, and require low maintenance.  Adversely, they do have large pressure losses with about 50% of the pressure drop not recoverable.  Continue reading “Flow Measurement with Orifice Plates”

The Operation of Gages and Switches in Hazardous Environments

In many industrial processes, the materials and the end product or by-products of the process, such as dust or vapors, can create conditions for a hazardous environment. Processes that have potential for hazardous environments include: water treatment, oil drilling, gas and chemical processing, power generation, pharmaceutical, and food manufacturing. The measurement and control of these processes are essential in maintaining optimal conditions of the manufacturing system and preventing catastrophic events.  Continue reading “The Operation of Gages and Switches in Hazardous Environments”

The Making of a Market Leader – The Magnehelic® Differential Pressure Gage

The name of the Magnehelic® Differential Pressure Gage was derived from the terms Magnet and the Helix. The Magnehelic® Gage is a simple yet elegant solution, which solved a problem faced by customers who wanted to measure low differential pressure. Historically the industry measured differential
Molded Plastic Manometers Series Mark II

pressure with a liquid filled manometer. The manometer worked on the principle that the difference in air pressure is measured as a function of gravity and liquid density. The challenge, however, was that the liquid in the manometer evaporates over time. This means that individuals would need to regularly add more liquid and re-calibrate the device. Continue reading “The Making of a Market Leader – The Magnehelic® Differential Pressure Gage”