Harwil's Q-Series fluid flow switches are made from numerous wetted materials, ranging from red brass, 316 stainless steel, Hastelloy C-276, Noryl (PPO), and Fortron (PPS), and accommodate fluids from pure water to strong acids and bases. The flow switches offer electrical ratings from dry cricuit to 15 amp, pressure ratings up to 300 psi at 250 degrees Fahrenheit, and pipe sizes 0.75" and greater.

RCM manufactures Flo-Gard in-line flow switches suitable for measuring oil, water containing contaminates, gases, and steam. UThe flow switches operate on the differential pressure principle and have no bearing or sliding services. They are also available in sizes from 0.25" to 8", and can be constructed from either bronze of 316 stainless steel.

Dwyer Instruments offers a full line of flow switches. Paddle flow switches include the Series FS-2, V4 Flotect vane operated, V6 Flotect mini-size, V7 Flotect vane operated, V8 vane operated, and V10 Flotect mini-size. The shuttle/piston flow switch options are the Series AFS adjustable, G9 globe, GVS globe valve, P1 brass, P2, P3 polypropylene, P4 PPS piston, P5 PVC shuttle, and many others.

Thomas Products designs and manufactures hundreds of standard flow and level switches. Usually constructed from solid-non-porous brass of stainless steel, these flow switches are designed for use with a large spectrum of clean, contaminated, or corrosive industrial fluids and eliminate leaks into electrical chambers.

Innovative Solutions offers three models of flow switches. The F001 sub-compact comes in brass or 316 stainless steel, and is rated to 1,000 psig. F002 piston types also come in brass or stainless steel and is rated up to 1,000 psigs, with flow settings between 0.2 GPM and 1.5 GPM. The F003 Series in-line model, available in a bronze body with a Teflon shuttle mechanism, monitors flow rates up to 50 GPM.

Gems Sensors and Controls manufactures a line of flow switches for use with both liquids and gases that feature corrosion-resistant materials, stainless steel, Ryton, and other options for material construction. Special flow switches are also available for viscosity compensation and high pressure environments.

Omega Engineering offers an array of flow switches for air, water, or oil that are designed to meet specific standards. These switches allow for maximum flow rates between 0.5 and 200 GPM (or 5 to 1,000+ SCFM), maximum pressure settings from 100 to 5,000 psi, accuracy between 2% and 25%, and temperatures up to 599 degrees Fahrenheit. Switch types are available as either mechanical and thermal.

Sierra Instruments manufactures Innova-Switch flow switches for gaseous and liquid flow switching or liquid level control. The sensor and other wetted materials are 316L stainless steel, and feature all welded construction with no moving parts. The company offers a standard flow switch with a response time of 0.5-10 seconds.

Rheotherm flow switches by Intek provide switch protection in all types of liquids or gases, and are capable of monitoring various flow switch applications, from extremely low flow process additives to loss of flow protection in large water or air lines. These flow switches, which have no moving parts, are offered in four models. The general purpose 100CS is the lowest cost industrial option and comes with one SPDT relay; the 100FS, for hazardous locations, has one SPDT relay with an option for a second relay for high and low set points; the Model 400 has an insertion probe with MNPT fitting, and is meant for hazardous settings; and the 500 provides an in-line design with  one N.O. relay rated at 0.5 A at 200 Vdc max and choice of 0.0625" or 0.125" O.D. flow tube connections.

Orange Research manufactures fixed set-point flow switches with piston sensors for liquids. The company offers the 3000 Series with set points of 0.1, 0.25, 0.5, 0.75, 1.0 and 1.5 GPM and wetted parts in either brass or stainless steel. Products operate at a maximum pressure of 1,000 psig with an accuracy of 10% FS, 1% repeatability, 20% maximum dead band, and operating range between -20 and +200 degrees Fahrenheit. Dimensions are 1" x 1" x 2.75".