ABB Variable Area Flow Meters and Rotameters

All Rotameters or Variable Area Flow Meters or VA Meters for short, indicate flow by the force of a liquid, gas or steam supporting a "float". The tube is tapered so that the area between the float and the tube increases with the height, increasing the cross sectional area  which results in  the in the float settling out at various heights equal to the flow of fluid.

The variable area flow meters are also referred to rotameters, purge meters depending on the flow rate and application. The classic variable area flow meters had a glass tube, however all metal meters or armored flow meters and armored purge meters meters are all considered to be variable area flow meters.

Fischer & Porter meters are now made by ABB in the USA or Germany.
Buck Sales Inc is an authorized distributor of ABB, Fischer & Porter, Bailey rotameters, purge meters and armored variable area flowmeters.

Fischer and Porter Flow Meters

Fischer & Porter, Bailey, are now part of ABB.
Older flowmeter and recommended replacemants can be found here

Selection Guide

Click on image for a larger view of the ABB selection guide

GLass Tube Purge Meter

Glass tube purgemeter (Sizes 1, 3, 5, 10") with ¼" NPT connections, Snap-in tube and protective shield, ball check valve, needle valve at inlet or outlet. Optional alarms & constant flow regulator.

Armored Purge Meters

Armored purgemeters for low flows of aggressive fluids and high temperature and pressures applications . Available with alarms and 4-20 ma transmitters (Sizes ¼, ⅜, ½, 1") with NPT threads. Integral needle valve option on ¼" size.

Kynar End Fittings

The 10A61 is available with kynar end fittings and other materials of construction for fluids that attack stainless steel

Flanged Armored Meters

ABB FAM 540 series armored variable area flow meters (rotameter) (Sizes ½ to 4") have flanged connections, and are used to measuring aggressive, opaque, non-conductive fluids. Can be configured with optional alarms, transmitter, configurable digital display, totalized pulse output & HART communications.

10A4500 [2%]
Glass Tube Rotameter

Glass tube rotameter (Sizes ½, ¾, 1, 1½, 2") with NPT or flanged connections, Snap-in tube and protective shield, Optional alarms. Used for monitoring fluid flows (gas or liquid) in variety of applications.

10A4600 [2%]
Glass Tube Rotamete-PVC 

ABB Series 10A4600 is a glass tube rotameter (variable area flow meter) similar to the 10A4500 model but with PVC end fittings, with the option of stainless steel, tantalum and ptfe or PVC coated floats.


10A2235 Glass tube rotameter - RATOSIGHT™ is available (Sizes 1/4, 1/2, 1, 2") with NPT threads and offers unique piping arrangements to fit most applications due to its hollow bronze body and multiple connections. Optional alarms can be added.

10B4500 [2%]

By-pass meter can be used where the pipe and flow rate is too large for a direct through meter. It uses the differential pressure across an orifice place to drive a precalculated amount of fluid theough the glass tube rotameter installed in the orifice taps

Alarm Module/Amplfier

The low level alarms are intrinsically safe for Class I, Div. 1, Group A, B, C & D and Class II, Div. 1, Group E, F & G when connected with the control amplifier mounted in non-hazardous location. Provides 120, 220 VAC and 24 VDC 2A contacts

Rotameters are also known as variable area flow meters and include a wide variety of flow meters under different names. The term variable area flow meter or VA meter comes from the cross sectional area increases along the length of the tube which results in  the float settling out at various heights equal to the flow of liquid or gas.

The classic rotameter, the glass tube rotameter is the 5 to 10" long meter with a float made of stainless steel or other material. For applications requiring higher pressures and temperatures the glass tube was replaced by a stainless steel tube which goes by various name of armored flow meter, metal tube rotameter, metal tube flow meter, flanged armored meter, etc.

A smaller version of the glass tube rotameter with tube lengths varying between 1.5 to 10" with smaller diameter tubes and floats were developed for low flow applications and since these were often used for purging they are also called purge meters, glass tube purge meters and low flow meters,  Again, to meet higher pressures and temperatures the glass tube was replaced by  stainless steel and these smaller meters are called armored purge meters.

For local indication the rotameter is a simple, cost effective choice, it can be used to measure flow of  a wide variety of liquids, gases, vapors and even steam. It is low maintenance and does not need electrical power to operate.

Over time additional functions of alarming and analog transmitters have been added to increase it functionality.

Following the acquisition of Fischer & Porter, ABB brings its considerable scope and power to offer a wide range of world-class rotameters. Today we have one of the highest global install rates, as well as one of the largest customer bases and broadest ranges of rotameters. Our network of distributors provide the user with fast delivery, widespread parts availability and solid service support.

Rotameters, also known as variable area flow meters, are designed to measure the flow of liquids or gases via a tapered tube and float system. They are accurate, reliable and simple to install and maintain. The main benefit is  their low cost, which has made them a popular choice for many flow applications since Fischer & Porter introduced the first mass- produced glass tube flow meter in 1937.

Prop 65 WARNING: Cancer and Reproductive Harm -