ACCESSORIES FOR PSA ONLINE AND OFFLINE INSTRUMENTS FOR Hg IN NATURAL GAS

P S Analytical have developed a range of accessories for your Online and Offline Instruments.

WET GAS FLOW METER

wetgasflowmeter

This model of the wet gas flow meter works on the principle of positive displacement.

It consists of a compartmented drum in a gas tight housing. The housing can be filled with water or oil. Antifreeze components can be added when used at low temperatures to avoid freezing.

The gas inlet and outlet are arranged so that the gas must pass through the space above the fluid displacing the water with gas sample, thus forcing the drum to revolve. A calibrated pointer within an eyeglass defines the quantity of fluid in relation to a calibrated gas volume.

The meter pressure rating must not exceed 200 mbar. The recommended upper flow rate for this type of meter is two revolution of drum per minute. This flow will provide an accuracy of ± 0.25%.

The advantage of the wet gas flow meters is that they operate independent of gas density and are therefore suitable for use with hydrocarbon gas mixtures. The final reading should be normalised for temperature and barometric pressure.

When supplied the meter will be provided with a calibration certificate traceable to national standards. In order to maintain accuracy the meter should be calibrated annually.

ROTAMETER

s665r018

A rotameter consists of a tapered tube, typically made of glass with a 'float', actually a shaped weight, inside that is pushed up by the drag force of the flow and pulled down by gravity.
Drag force for a given fluid and float cross section is a function of flow speed squared only.

A higher volumetric flow rate through a given area increases flow speed and drag force, so the float will be pushed upwards. However, as the inside of the rotameter is cone shaped (widens), the area around the float through which the medium flows increases, the flow speed and drag force decrease until there is mechanical equilibrium with the float's weight.

PRIMARY PRESSURE REDUCTION SYSTEM

10640

The PSA 10.640 series Primary Pressure Reduction (PPR) Systems are designed to reduce the pressure of sample streams prior to a sampling system.  Primary Pressure Reduction systems are typically used to decrease the pressure of hydrocarbon sample streams prior to sample transport to the 10.540 series Online Sampling System or PSA 10.547 Offline Sampling System.  Reasons for using Primary Pressure Reduction include:

  • Vaporisation of liquid phase process streams

  • Reduced pressure in sample lines

  • Staged pressure reduction reducing risk of condensation

  • Reduced lag time compared to high pressure sample transport

  • Reduced consumption of sample for bypass flows

For liquefied sample streams such as LPG or butane, flash vaporisation using a PPR close to the sample point is recommended to avoid the use of liquid bypass configurations.

A Primary Pressure Reduction comprises an insulated heated pressure regulator, suitable for use in a zone 1 or 2 hazardous area, (ATEX and IECEx Certification available) a 7 µm pre-filter to prevent particulate from the sample stream entering the regulator, a gauge to view the outlet pressure and associated stainless steel fittings.  (Connections are ¼ in. compression fittings.)

The PPR systems have been proven for sampling mercury in hydrocarbon sample streams.  Heating the regulator overcomes Joule-Thomson cooling, preventing condensation and losses in the cooled sample stream.  The unique spiral machined heater sheath in the heated pressure regulator ensures efficient heat transfer to avoid condensation occurring the in the regulator.  For sample streams with very low mercury concentrations and/or highly variable concentrations, SilcoNertTM coated PPR systems are optionally available.

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PRIMARY BYPASS FLOW CONTROL AND INDICATION KIT

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The PSA S540K100 Primary Bypass Flow Control and Indication Kit is designed to operate in conjunction with the PSA 10.540 range of online sampling systems.  The kit provides everything required to control and monitor the flow on the primary bypass for a single channel in the sampling system. 

Two different kits exist. The kit which is suitable for a given application depends on the sample line pressure (after primary pressure reduction, when used) and the sample matrix, e.g. (for natural gas):

Model

Matrix

Pressure Range

S540K100

Natural Gas

≤ 59 bar g

S540K110

Natural Gas

> 59 bar g

Maintaining continuous flow through each channel of the sampling system is necessary to ensure that a representative sample is available for analysis.  To minimise sample line lag time, P S Analytical suggests a flow rate of 10 L min‑1 actual flow be maintained in the sample line.

The Primary Bypass Flow Control and Measurement Kit includes an armoured metal tube variable area flowmeter, sized and calibrated for a sample flow rate of 10 L min‑1 (actual) in the sample delivery lines, a needle value for flow control, all mounted on a stainless steel plate to facilitate installation.

Connection types:

Inlet     ¼ in. compression fitting
Outlet  ¼ in. compression fitting

A pressure differential is required between inlet and outlet to ensure adequate flow.

s540k100

SEMI AUTOMATIC CHANGEOVER PANEL

n670a100

The semi-automatic changeover panel allows the simultaneous connection of two carrier gas cylinders (or cylinder banks) to an online analyser, with automatic changeover from one cylinder to the other as the first cylinder is depleted.  It can be used with either argon or nitrogen carrier gas.

The panel consists of two single stage pressure regulators built into a single body, which are set to allow a continuous gas supply from two cylinders.  The main regulator (left-hand side) is set to a pressure 2 bar higher than the standby regulator (right-hand side).  As the pressure from the main cylinder falls, the backup regulator automatically cuts in provide the gas flow.  When the handle is turned back to the main regulator, the inlet pressure continues from this side.  The cylinder in use is indicated by an arrow on the selection handle.

An outlet regulator, including a safety pressure relief valve is included at the outlet of the auto-changeover to regulate the gas supply to the required output pressure.

The auto-changeover panel incorporates full safety-pattern gauges, indicating each cylinder’s contents and the output pressure; isolation valves for each side and the outlet and high pressure vent valves to facilitate cylinder replacement.  Non-return valves, 1 m long high pressure hoses with anti-whip cables and cylinder connectors are also included for each side.

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N670P100 SERIES DIRECT DRIVE MEMBRANE PROBE WITH REGULATOR

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The N670P100 Series Direct Drive Membrane Probe with Regulator are low dead-volume adjustable length, membrane tipped probes incorporating a pressure regulator for sampling Natural Gas and other Hydrocarbon streams.

Product Highlights

  • Protects sampling system and analyser from liquid and particulate contamination.

  • Direct pressure reduction within the pipeline

  • Easy, quick and safe insertion and extraction from pressurised systems.

  • Adjustable length probe

  • Horizontal or vertical mounting

  • Spiral design and non-rigid attachment resists vibration and negates the need for wake calculations

 

N670P200 SERIES DIRECT DRIVE MEMBRANE PROBE

n670p200

The N670P200 Series Direct Drive Membrane Probes are low dead-volume adjustable length, membrane tipped probes for sampling Natural Gas and other Hydrocarbon Gas streams. The N670P200 Series Probe does not include a Pressure Regulator.

Product Highlights

  • Protects sampling system and analyser from liquid and particulate contamination.

  • Easy, quick and safe insertion and extraction from pressurised systems.

  • Adjustable length probe

  • Horizontal or vertical mounting

  • Spiral design and non-rigid attachment resists vibration and negates the need for wake calculations

N670P300 SERIES DIRECT DRIVE PROBE

n670p300

The N670P300 Series Direct Drive Probes are low dead-volume adjustable length, probes for sampling liquids, Natural Gas and other Hydrocarbon streams.

The N670P300 Series Probe does not include a pressure regulator or membrane filter; the sample outlets unfiltered and at process pressure.

Product Highlights

  • Easy, quick and safe insertion and extraction from pressurised systems.

  • Adjustable length probe

  • Horizontal or vertical mounting

  • Spiral design and non-rigid attachment resists vibration and negates the need for wake calculations

PSA G525T400 TRAP CLEANER

The PSA G525T400 Trap Cleaner Module is designed to be used as a stand-alone module commenting a Sir Galahad System.

g525t400

Product Highlights:

  • Prepare new or used Amasil gold traps for mercury collection

  • Allow higher analytical throughput by removing multiple cleaning steps using the Sir Galahad

  • Allow preparation of tubes ahead of time to increase productivity

  • Protect the Sir Galahad from contamination problems posed by used/dirty collection traps

  • Cost effective. Clean all your traps and only keep those with low blanks

 

To discuss particular requirements and for more detailed information on the above accessories please complete the Information Request Form.