Current position > Product detail
『Bailey Flow Meter: Sourcing Historical Differential Pressure Process Controls』Related information(flow rotameter|digital flow meter|balo meter|hydraulic flow meter|volumetric meter|positive displacement meter|pitot tube flow meter|displacement meter|cfm meter|variable area flow meter|inline flow meter|differential pressure flow meter|calibrated flow meter|velocity meter|paddle wheel flow meter|oval gear flow meter|anemometer hvac|multiphase flow meter|doppler flow meter|thorpe tube flowmeter|heat flow meter)
Bailey Flow Meter: Sourcing Historical Differential Pressure Process Controls
Quick Answer: Silver Automation Instruments supplies modern differential pressure transmitters and complete flow meters for legacy Bailey flow meter loops. A typical replacement uses 4 to 20 mA HART output and square root extraction, with ranges from 0 to 25 mbar and 0 to 400 bar. Send your orifice plate data, pipe size, pressure, and temperature for a quote.
What Is a Bailey Flow Meter Loop?
Bailey flow meter loops are common in older power plants, steam networks, and chemical sites. The original Bailey DP cells measured differential pressure across an orifice plate, venturi, or pitot tube. Many units from the 1970s and 1980s still run today. They often use pneumatic 3 to 15 psi signals or 10 to 50 mA DC loops. Technicians know these loops well. Sourcing historical differential pressure process controls becomes a problem when an old Bailey transmitter fails and spare parts are hard to find.
Most engineers skip the idea of rebuilding the old cell. In practice, a modern DP transmitter is faster to install and easier to calibrate. We have seen this on customer sites many times. A new transmitter can connect to the existing orifice plate and impulse lines. That keeps the piping untouched.
Common Issues with Legacy Bailey DP Cells
Old Bailey DP cells have wear points. Diaphragms crack after decades of thermal cycling. Calibration drifts. Pneumatic flapper nozzle systems clog. Spare parts are scarce in Southeast Asia, Latin America, and Africa. We have had customers wait weeks for a single seal kit. That downtime costs more than a replacement transmitter.
Here is the thing. Some plants keep a shelf of used Bailey units. They swap parts and hope for the best. This works until two loops fail in the same month. A better option is to source a new differential pressure flow meter or transmitter with local support.
Replacement Options from Silver Instruments
Silver Instruments supplies the SDP series differential pressure transmitters. These cover differential spans from 0 to 25 mbar up to 400 bar. Accuracy is ±0.075 percent of span. Output is 4 to 20 mA HART with square root or linear function. The process connection is 1/4 NPT or 1/2 NPT. Wetted parts come in 316L stainless steel, Hastelloy C, or tantalum. Housing protection is IP66/IP67. Explosion proof versions meet ATEX Zone 1 and IECEx standards. We can supply DP transmitters for lines from DN15 to DN1200.
For liquid flow measurement where a DP orifice plate is not ideal, we also supply electromagnetic flow meters, vortex flow meters, and Coriolis mass flow meters. A water treatment plant in Vietnam replaced a Bailey DP loop on a DN300 raw water line with a Silver Instruments electromagnetic flow meter. The pipe had no straight run. The electromagnetic sensor worked better. For steam and gas, a vortex flow meter is often a direct replacement with lower maintenance. Silver Automation Instruments is a flow meter manufacturer and supplier based in China. We ship to Southeast Asia, Oceania, Latin America, Africa, and the Middle East.
Key Specifications to Check Before Ordering
Do not guess the range. Gather four data points be
_600x400.jpg)
We have seen customers in the Middle East order a DP transmitter with the wrong range because they copied a 40 year old tag plate. The tag plate can be misleading. So always verify actual process conditions with the control room operator. A 0 to 100 kPa span might work for a cold water line but not for a steam line at 20 bar. Some loops also need a PT100 temperature input for steam flow compensation. If the fluid is syrup or oil, include viscosity in cP.
Two Replacement Examples from Customer Sites
A palm oil refinery in Malaysia replaced two Bailey DP cells on steam boiler feed lines in 2023. The original units were pneumatic. We supplied SDP3051 DP transmitters with square root output and 316L wetted parts. The plant wired them to the existing DCS and finished the loop check in one day.
A chemical batch plant in Chile had a Bailey DP flow meter on a solvent line. The impulse lines plugged every few weeks. They switched to a Silver Instruments Coriolis mass flow meter. The Coriolis meter measured mass flow and density directly, with no impulse lines to plug. The line was DN25 and ran at 12 bar with flow range 0 to 1800 kg/h. That change cut maintenance time.
FAQ
Can Silver Instruments supply a direct replacement for a Bailey DP cell?
Yes. We supply SDP series differential pressure transmitters that work with the existing orifice plate and impulse lines. Most replacements use 4 to 20 mA HART output. We can add signal converters for older 10 to 50 mA or pneumatic loops.
What output signal do modern Bailey replacements use?
The standard output is 4 to 20 mA HART with square root or linear function. Some plants need pulse, Modbus, or 10 to 50 mA DC. We can quote those options.
Do we need the original orifice plate data?
It helps. Send the pipe size, orifice bore, beta ratio, and full scale differential pressure. If you do not have the drawing, we can help you size a new orifice plate or supply a different flow meter type.
What industries still run Bailey flow meters?
Power plants, steam networks, chemical sites, water treatment plants, and offshore platforms. Many Bailey DP loops in Southeast Asia and the Middle East are still active. Spare parts are the main issue.
What is the typical lead time for a replacement transmitter?
SDP series standard ranges ship in 7 to 12 days. Special wetted materials or flameproof certification may take 15 to 20 days. Send your requirements and we will confirm the exact lead time.
Send your pressure in bar, temperature in °C, pipe size in DN, and flow range to get a quote. Email through our website flow-meter.com.au. You can also call Tel: +86-135-1213-1526 or WhatsApp: 86-135-12131526. For WeChat use +86 13512131526. We reply within 24 hours on working days.