Industry
Corrosion-resistant flow, pressure, level and analysis instrumentation for reactors, columns and dosing systems.
A chemical plant punishes instruments with corrosion, crystallisation, fouling and temperature, so the specification ends up being written around the medium rather than around the measurement. The wetted-material and sealing decision usually matters more than the accuracy grade, because an instrument of modest accuracy with the right wetted face keeps working, while a precise one with the wrong one fails within weeks.
The sector also splits along a line that has nothing to do with chemistry: batch against continuous. A batch reactor asks for fast response and repeatable dosing, because the quantity added in a short window is the figure that matters. A continuous column or pipeline asks for drift stability over months, because nobody will recalibrate a unit that runs continuously and the accumulated error is what eventually shows up in the site balance.
Most of the difficulty arrives before the instrument is chosen. A medium that crystallises, a vapour space that condenses, a reagent that requires a lined pipe, a seal that has to isolate the transmitter from the process entirely - each of those is a decision about the installation, and each one changes what can be specified. An enquiry that states the medium, the concentration and how it behaves is answered far more precisely than one that names the measurement alone.
Reactors, autoclaves and crystallisers, where temperature and pressure are the controlled variables and agitation makes level and interface measurement difficult. Corrosion and crystallisation are routine, and the instrument is often mounted through a nozzle where access is limited.
Columns, evaporators, extractors and filters. Differential pressure across packed beds and trays is a recurring duty, and the composition changes from stage to stage, so one material specification rarely covers a whole unit.
Tanks, day tanks and dosing skids. Level and flow dominate, and the quantities are frequently small and repeated, which places the emphasis on repeatability rather than on a wide range.
Cooling water, steam, nitrogen and the effluent treatment that closes the site. pH, conductivity, flow and level are measured here under a regulatory obligation as well as a process one, so the record matters as much as the reading.
| Measurement | What is measured in this sector | Instruments commonly specified |
|---|---|---|
| Flow | Reagent dosing, corrosive liquids and slurries, solvent transfer, cooling water and steam | Electromagnetic meters with the lining matched to the medium, Coriolis meters for dosing and mass, vortex or differential-pressure installations for steam, and positive-displacement meters for viscous and dosing duties |
| Pressure | Reactor and column pressure, vapour pressure, and differential pressure across beds, filters and strainers | Pressure and differential transmitters with diaphragm seals and capillaries so that the transmitter never sees the process, and with the fill fluid chosen for the temperature at the tapping |
| Temperature | Reaction temperature, column and condenser profiles, and the temperature used to compensate flow and analysis readings | RTDs in thermowells where stability is wanted, thermocouples where the duty is hot and fast, and surface or non-contact measurement for vessels that cannot be tapped |
| Level and interface | Tank inventory, reactor level under agitation and foam, and the boundary between two immiscible liquids | Radar and guided-wave transmitters, hydrostatic transmitters where the vessel is simple, interface instruments where a phase boundary is the reported figure, and independent switches for protection |
| Analysis | pH, ORP, conductivity, dissolved oxygen and moisture in reaction, utility and effluent streams | In-line analysers and transmitters with the electrode or cell selected for the chemistry, plus the sample conditioning that has to sit in front of them |
| Gas and vapour | Combustible gas, toxic gas, oxygen deficiency and vapour concentration in process areas, tank farms and dosing rooms | Fixed detectors with the sensor type matched to the target gas, and portable instruments for entry and maintenance work |
The list is a starting point rather than a quotation. In this sector the wetted material, the seal arrangement and the area classification narrow the choice faster than the measurement itself does.
Frequently asked
The questions that come up in this sector before an order. If yours is not here, send it with the duty and we will answer it alongside the quotation.
Because an instrument that corrodes or fouls stops measuring entirely, while one of modest accuracy continues to give a usable figure. In chemical service the material and the sealing arrangement decide whether the instrument survives the first months, and the accuracy class only decides how good the reading is while it does. Send the medium, the concentration and the temperature, and the material comes first in the answer.
It isolates the transmitter from the process, transmitting pressure through a thin diaphragm and a fill fluid so that the measuring element only ever sees a clean, known medium. It is used where the process would block, corrode or crystallise on the element, and also where the process has to be kept out of the instrument for cleanliness or safety reasons. The fill fluid, the capillary length and the temperature all become part of the measurement once a seal is fitted.
Agitation, foam, baffles and internal fittings all disturb or reflect an echo, so the technology is chosen for what the vessel actually does rather than for the product alone. Radar is common because nothing enters the product, but the antenna and the mounting position matter, and a low-dielectric medium with heavy foam can defeat it. Where the vessel also has to report an interface, the answer changes again. Describe the agitation and the internals with the enquiry.
Rarely well. A batch duty rewards a fast response and a repeatable zero, while a continuous duty rewards stability over a long period, and instruments tend to trade one against the other. Where a site runs both, it usually ends up with different instruments for the two duties. Say which applies at each point rather than describing the plant as a whole.
By the quantity per dose, the interval between doses, the repeatability needed and the viscosity of what is being dosed. Small repeated additions place the emphasis on repeatability and on response rather than on a wide measuring range, and a viscous or pulsating medium frequently rules out the technologies that would be obvious for a clean liquid. State the dose size and how often it is repeated.
The medium and its behaviour - concentration, solids, crystallisation and temperature - plus the measurement, the range, the process connection standard and the area classification. Where a project material standard exists, send it, because it decides the wetted materials before the instrument does. Those answers usually settle the specification, and the remaining questions are commercial.
Published products
BAL-220 · Laboratory Balances Reference listing
Analytical balance with a 220 g capacity and 0.1 mg readability, an electromagnetic force compensation cell and an internal calibration weight.
EFM-100 · Electromagnetic Flow Meters Reference listing
Obstructionless full-bore flow meter for conductive liquids from 4-20 mA or pulse output, with a lined wetted path that adds no pressure drop.
MGD-4 · Portable Gas Detectors Reference listing
Four-gas personal detector with a pumped or diffusion inlet, audible and visual alarms, and a datalog for confined space entry and plant rounds.
PCAL-60 · Pressure Calibrators Reference listing
Handheld pressure calibrator combining a hand pump and a reference sensor, generating pressure and measuring the transmitter output in a single instrument.
PHA-300 · pH Analyzers Reference listing
Continuous pH measurement with automatic temperature compensation, a differential or combined electrode and a 4-20 mA output for control or recording.
PTX-200 · Pressure Transmitters Reference listing
Two-wire 4-20 mA pressure transmitter with a stainless steel wetted diaphragm, available in gauge, absolute and compound ranges for process and utility duties.
RLM-80 · Radar Level Meters Reference listing
Non-contact radar level transmitter for liquids and bulk solids, measuring through vapour, dust and foam without touching the medium.
RTD-PT100 · RTD Temperature Sensors Reference listing
PT100 resistance thermometer assembly with a stainless steel sheath, available in two, three and four-wire configurations for process and laboratory duty.
UTG-5 · Ultrasonic Thickness Gauges Reference listing
Portable ultrasonic thickness gauge measuring remaining wall thickness of metals and plastics from one side, for corrosion survey and inspection work.
UVS-1900 · Spectrophotometers Reference listing
Double-beam UV-Vis spectrophotometer covering 190 to 1100 nm with a scanning monochromator, for quantitative analysis and wavelength scanning in the laboratory.
Send the process conditions and the standard you have to meet, and we will confirm the instrument, availability and documentation that can accompany the order.
Request for quotation
Send the technical detail and we will confirm availability, lead time and terms. In-stock items ship within 48 hours; customized specifications typically take 2-10 days. Minimum order quantity is 1 pc.