Gas Sampling Bags

Features

  • Non-permeable
  • Opaque – to protect collected gases against ultraviolet light
  • Do not chemically interact with gases
  • Strong enough to withstand rough and repeated handling
  • Purging possible by use with 2 valves positioned diagonally at opposite side in bag corners
  • Withdrawal of gas sample by use of syringe with septum or replaceable septum
  • Do not become brittle or otherwise deteriorate over time
  • Simple to maintain and do not require technical training to operate
  • Virtually unlimited shelf life

Application

RITTER air/gas sampling bags have been specifically designed for easy and reliable collection of air & gas samples. The non-permeable, opaque and chemically inert properties of the bags ensure that the collected gases remain uncontaminated and unaltered.

The sampling bags provide a simple and economical method of collecting and transferring air & gas samples from any collection point to a centrally located test instrument or laboratory for analysis. They are, therefore, ideal for use in hard-to-reach locations.

The bags can also be used to collect vapours, or may be used with odour test panels.

When using gas sampling bags, it may not be necessary to keep track of the precise volume collected or the elapsed time required to obtain the sample. Correct use of the bags results in a collected sample that is representative of the environment or process medium from which it was collected (taken), either as a grab sample or a Time Weighted Average.

Further, using sophisticated expensive, real-time gas analysis techniques to establish concentration levels generally means being restricted to one fixed monitoring point. In contrast, totally portable gas sampling bags permit absolute freedom of movement and measurement over a wide area of sample points. Determining if and where a gas or pollution problem exists becomes an easy and inexpensive task.

Design

Any gas sampling bag technique is dependent upon the quality of the sampling bag used. The construction and materials of the RITTER Gas Sampling Bags ensure the physical integrity of any sample taken, and allow it to be stored without change over time. Thus, the collected sample remains truly representative of its collection environment or medium conditions.

In contrast to other single- or multiple-layer plastic materials in use, these silvery bags are made by a special production process and contain six different layers of materials:

  • Polyethylene terephthalate (outside)
  • Polyethylene
  • Aluminium Foil
  • Polyamide
  • Polyethylene
  • Polyethylene (inside)

The layers are bonded together to form a single flexible material of 131 micrometer thickness.

Pressure & Temperature

The sampling bag inflation pressure need not exceed 0.25 psi (17.4 mbar). Bags should not be over-inflated, as this may lead to bag failure. When bag samples are air transported, provision should be made for gas expansion at higher flight altitudes.

Bags should not be used at temperatures higher than 50 °C – 55 °C (125 °F – 130 °F). All polymer based gas sampling bags should be handled with extra care when used at any temperature above ambient, particularly above 40 °C – 45 °C (110 °F – 115 °F).

If high-temperature stack gases are to be collected, sample line tubing should be long enough to allow the sampled gas stream to cool before entering the bag.

Bag types

RITTER Gas Sampling Bags are available in pillow shape. They are available in standard sizes up to 200 litres. The bags can be manufactured in any size and type to meet individual specification.

Description Shape Volume (1) Width Length
GSB-P/ 0.1 Pillow 0.1 ltr 76 mm 127 mm
GSB-P/ 0.5 Pillow 0.5 ltr 152 mm 203 mm
GSB-P/ 1(2) Pillow 1.0 ltr 203 mm 203 mm
GSB-P/ 2 Pillow 2.0 ltr 203 mm 305 mm
GSB-P/ 5 Pillow 5.0 ltr 203 mm 584 mm
GSB-P/ 10 Pillow 10.0 ltr 381 mm 406 mm
GSB-P/ 15 Pillow 15.0 ltr 400 mm 508 mm
GSB-P/ 22 Pillow 22.0 ltr 406 mm 610 mm
GSB-P/ 44 Pillow 44.0 ltr 584 mm 660 mm
GSB-P/ 60 Pillow 60.0 ltr 610 mm 800 mm
  • (1) Capacity equal or greater than volume in liters; volume defined at 7″ WS = 17,7 mbar
  • (2) 1-liter bags vary in shape, will be shipped as available in stock

Valves

If not specified differently, the Gas Sampling Bags will be delivered with standard valve “Twist-Type Double-O-Ring (V-NPB-2/OO), Figure 3”.

Standard Valve

Twist-Type Double-O-Ring (V-NPB-2/OO)


The Twist-Type Double-O-Ring Valve operates in the same way as the Twist-Type Valve (Figure 1). However, this valve has the special added feature of a secondary O-ring installed on the valve stem, greatly reducing or eliminating gas loss at recommended inflation pressures.

Optional Valves

Straight Through Connection (STC-NPB-F-SR)

The Straight Through Connection (STC) can be ordered as a standard feature instead of the Twist-Type valve. The Straight-Through Connection (STC) is any unobstructed gas channel connection that does not allow the user to control the flow of gas. Two STC’s may be used to allow a continuous flow of gas or liquid through the bag, if the bag is to be used as a buffer. Used in conjunction with another type of valve (inlet port), an STC may also be installed as an outlet purge-port, so as to permit a flow-through purge (cleaning) of the bag after each use. (In this case, for gas sampling, a short piece of tubing must be placed on the STC and a closing device (such as a plastic medical tubing clamp) then placed on this tubing.)

Luer-Fit Valve™ (V-L/F-1)

The Luer-Fit Valve™ is a secure, self-closing valve which cannot be opened or left open accidentally, thus preventing any loss of gas or liquid sample. It is easy to use and requires no turning or twisting of the valve stem.

The Luer-taper Quik-Mate™ Connector (shown above the Luer-Fit Valve™), standard with each Luer-Fit Valve™, is a flow-through adapter for instant (push-pull) connection of tubing to the valve. The tapered fitting between the valve stem housing and Quik-Mate™ Connector becomes tighter as pressure is exerted on the Quik-Mate. This ensures a gas-tight fit between the sample line tubing and the Luer-Fit Valve™.

Gases can be inserted or withdrawn through the use of either sample line tubing or a syringe with a Luer-taper barrel fitting. This valve can eliminate the need to work with syringe-needles, if desired. The Luer-Fit Valve™ is also compatible with our full line of sampling accessories, including the Hann-Pump™.

Please Note: Because of its tiny gas channels, the Luer-Fit Valve™ is not suitable for gases containing particles. It also has a lower flow rate than other valve connections at the same pressure. Further, one must be aware of „dead space“ which may occur when using a syringe with a needleless syringe barrel, to withdraw or inject sample gas or liquid through the valve-stem housing.

Replaceable Septum Holder (A-SEPHLD/DEL)

When a septum is affixed to a bag with an adhesive, every penetration of it by a syringe makes another hole in the bag. This leads to continued bag deterioration and reduces its useful life. An optional replaceable septum holder allows the user to change the septum as required. Replaceable septum holders are available in the following materials: Delrin, Nickel plated brass, and Polysulfone. Stainless steel is available on special order.