Rugged Sulfide-Resistant pH Sensors

Engineers and technicians looking for a flexible, cost-effective solution to monitoring sour water containing Hydrogen Sulphide (H2S) compounds in oil/gas refineries will find the sulphide-resistant Models S10 and S17 Analytical pH Sensors from Electro-Chemical Devices (ECD) help them keep their processes and plants running efficiently.

Petroleum refiners must take care to monitor and treat naturally occurring H2S that contaminates water in their operations to meet regulatory limits. Removing H2S from the water is done through air stripping that eliminates the sulphur or oxidation reactions that convert the sulphides to sulphates. Once the water has been stripped of the sulphides it can be used in other refinery operations or be further treated as wastewater. Stripping is essential due to both the toxic environmental and corrosive effects on equipment of sulphides, which are also a common sensor poison.

ECD’s S10 and S17 pH Sensor product family monitor pH in water-based solutions. The S10 and S17’s Model 20005130 replaceable cartridge electrode features a pH range of 0 to 14 at temperatures from -5 to 130◦C and survives pressures up to 300 psi at 25◦C. It has been tested to sulphide ion concentrations of up to 25ppm.

The S10 and S17 product line consists of two unique sensor designs and replaceable electrode cartridges. The S10 Sensor is an immersion or an insertion style sensor, and the S17 is a valve retractable style sensor. They are fully rebuildable and feature a 316 stainless steel body that incorporates the sensing cartridge, a temperature module and a signal conditioner with cabling. These cartridges provide specific solutions for the measurement of pH, ORP, specific ion (pION), dissolved oxygen, conductivity and resistivity in a wide range of industrial process applications.

The pH and ORP cartridges are available with either Radel (PES) or PEEK construction configurations with full crown, double or single tine style pH bulb protection. The pION cartridges with solid state, glass or PVC sensing membranes are suitable for continuous online measurement. The DO electrode is a galvanic cell with a lead anode, silver cathode and Teflon membrane. The conductivity and resistivity electrodes are designed in both contacting and toroidal sensor configurations for application flexibility.