SafeTap II

Description

BOS SafeTap II Optical Oxygen Sensor

Product Overview

The Barben Analytical SafeTap II is a retractable or “hot tap” Optical Oxygen Sensor. It is used with the OXYvisor Oxygen Analyzer for in situ sampling methods. Designed for use in liquids and dry or wet gases, the SafeTap II can be manually inserted and retracted from the process line. The SafeTap II provides the capability of in situ installation of a selectable BOSx Oxygen sensor ranges into the process pipe or vessel.

Features and Benefits

• Uses optical quench luminescent technology, no cross-sensitivity to CO2, SO2, NH3, and H2S, not affected by high O2 levels and moisture, as compared to an E-Chem sensor
• Eliminates sample handling conditioning systems typical in extractive sampling methods. Lowers installation costs, complexity and maintenance.
• Adjustable BOSx sensor insertion length for variety of process pipe diameters
• RTD integrated at sensor tip for accurate temperature measurement and compensation
• Optional pressure transmitter allows for automatic compensation for accurate in-line measurements
• T-Handle and safety hook prevents blow-outs in-case of unplanned overpressure and ensures safe operation during insertion and retraction
• Replaceable BOSx sensor cap—simple and quick sensor cap service replacement design
• Approved for Hazardous Location installations
  • Fiber Optic O2 light energy is certified “op is” (optically inherently safe)
  • RTD is simple apparatus for C1D2 or Zone 2 and carries OXYvisor specifications (See OXYvisor datasheet or drawings for hazardous location)
  • RTD in Zone 1, requires special Exd considerations

Typical Applications

• Biogas – wet digester gas. 100 % compatible with typical stream compositions CH4, CO2, H2O, H2S, N2, O2, NH3 & H2
• Biogas – H2S removal/sweetening, amines or bio scrubber
• Renewable Natural Gas (RNG) – upgraded biomethane trace O2 (ppm) measurement for transmission quality pipeline gas
• Carbon capture processes in CO2 (trace and % level O2)
• EOR – Enhanced Oil Recovery – Waterflood PPB Dissolved O2 for seawater down hole injection
• General replacement of E-Chem (electrochemical / fuel) cells for Trace O2 ppm to % level measurement
  • Not affected by typical e-chem poisons (H2S, CO2, H2)
  • Measurement accuracy independent of flow rate
  • Not affected with exposure to air or high O2
  • Accurate measurement in particulate (dirty) streams

Principle of Operation

Figure above illustrates the SafeTap II assembly with optional pressure transmitter (1) installed on the flow cell for continuous measurement of pressure in the process line and during calibration process for gas phase measurements. The BOS SafeTap II oxygen sensor comes standard with integral Pt100 RTD (5) temperature sensor suitable for Class 1 Div 2, or without using an external RTD for Zone 1. The SafeTap II is rated up to pressures of 750 psig (51.7 Bar). Built in tubing ports are included as part of the welded retraction housing so that purge and complete in situ calibration, in normal process operating conditions, and 450 psig (31.0 Bar) during Insertion and Retraction of the SafeTap II, may be performed without removal of the oxygen sensor.

For inserting and retracting, the free rotating Safe-T-Handle (2) provides a secure gripping surface to manually insert and retract the optical sensor assembly into the process. The SafeTap II includes a security hook (3) that catches the safe-T-handle to prevent unintended retraction. The 316SS Ball Valve (4) eliminates the need for a secondary isolation valve for retracting or maintenance of the sensor. Optional calibration gas inlet and outlet 316SS needle valves provide ease of manual calibration.

The SafeTap II is supplied with a replaceable luminophore window sensor cap (6), making sensor service simple and low cost. When sensor cap replacement is required, the removable luminophore tip can be retracted through the ball valve
(4), which is used to isolate the sensor from the process. The sensor cap can be simply unscrewed with your fingers or hand and the replacement screwed back on hand tight, do not use any tools.

For a more thorough and detailed process on inserting, retracting the sensor assembly, calibration, and sensor cap replacement, please review the SafeTap II Oxygen Sensor Manual.