Written by Melvin Tan
March 11, 2022

Reliable and accurate sampling system for natural gas applications

My previous article in this series explained what are the main issues in obtaining a representative sample in NG applications.

This case study demonstrates a reliable sampling solution currently used by plant operators. It helps plant operators to obtain representative samples.

Customer challenge

Sampling system is difficult to install and maintain. Furthermore, it does not provide reliable and accurate analysis results.

Running an efficient operation requires reliable, real-time data. That data can be obtained through representative sampling.

The typical sampling arrangement, in a natural gas plant, consists of a flanged end probe extractor, a flanged ball valve, and the measuring instrument. This setup presents several challenges to the plant operators:

Traditional setup is very bulky. It requires several man hours and accessories to assemble.
There are multiple connection points between different components of the traditional setup. These reduce the reliability of the system due to a large number of possible leakage paths.
In order to obtain a representative sample, gas must be drawn from a well-mixed point within the pipeline. The gas near the sidewalls of the pipeline may contain contaminants that could affect a correct reading.
The gas that flows into the sampling system must flow back to the main pipeline, without on-site personnel coming into contact with the media. The sampling therefore requires an isolated looping design. Such a design can further increase the number of components and possible leak paths.
Servicing or replacement of a component in the sampling system requires production to be stopped. Only afterwards can the system be disassembled.

The solution

We customized the sampling valve to customer needs.
Our sampling valve helps the plant operators obtain representative samples safely & reliably. Furthermore, it reduces installation and maintenance costs.

Requirement description

AS-Schneider offers sampling and injection valves. These valves help meet some of the challenges mentioned above such as a compact design and fewer potential leakage paths.

Companies in the natural gas supply chain that were already using these products approached AS-Schneider for a customized product that would completely meet their specific needs.

In response to customers demand, AS-Schneider went back to the drawing board to address these issues. The sampling valve design was used as a starting point; modifications were incorporated in the base design to resolve the issues faced by their clients.

Target specifications

The main objective of the redesign was to make the valve suitable for measuring devices that require a looping flow.
Another important design target was to allow the product to be retrieved from a well-mixed point within the pipeline. Besides, it should not be placed on the sidewalls.
Furthermore, it was important to ensure that the modifications allowed for maintenance and service of the sampling setup without the need to stop production.

Design and arrangement of the customized sampling valve

Our experts have successfully modified the design of the sampling valve. The customized sampling valve smoothly meets all the requirements of the natural gas industry.

The following illustration shows the design and application of the AS-Schneider natural gas sampling valve.

(1) The flange at the bottom connects the valve to the main pipeline.

(2) A sampling probe, with an adjustable length, extends through the flange into the main pipeline.

(3) The tip of the probe can be positioned away from the pipeline wall to ensure that a representative
sample is drawn.

(4) The opposite flanged end of the valve is connected to the sampling system that receives and stores
the sample.

(5) The integrated valve can be used to isolate the sampling system from the main pipeline during
maintenance.

(6) The return line from the sampling system is connected to the flange on the right which takes the
unused gas back to the main line.

Features of the customized sampling valve

The customized sampling valve offers the following features:

Integral Body
Fewer possible leak paths due to fewer connections
Compact design minimizes overall weight
Suitable for measuring devices that require looping application
Reduced installation time
Fully customizable valve design and probe length
Available in a range of materials that allow its use in harsh environments

5 amazing benefits of the customized sampling valve you should know

The customized sampling valve helps plant operators obtain representative samples safely and reliably. Furthermore, it reduces installation and maintenance costs.

A sampling system based on these valves offers following benefits to plant operators.

#1

Consistently high product quality and strict regulatory compliance

In order to ensure product quality and regulatory compliance, a process must be operated within its design parameters. The process can only operate within the specified parameter range if the parameter values can be accurately measured and controlled.

The customized sampling valve design with customized probe length ensures that the sample is drawn from a well-mixed point and is representative of the gas flowing in the system. The measurements obtained using the system are accurate and can be relied upon to take any necessary actions for process control. This measurement and control cycle ensures that the product quality goals are met. The manufacturer does not contravene any regulatory requirements.

#2

Reduced downtime and wastage

Process monitoring through the customized sampling valve ensures efficient plant operation & maximum output.

Unplanned downtime can be minimized by timely detection of any deviation from the standard. This prevents production losses, waste or damage to valuable equipment.

#3

Process optimization

Representative samples obtained using the customized sampling valve can be used to optimize a process. Thereby you can reduce the energy consumption and minimize the processing time.

By means of representative sampling, an issue can be detected in time. The plant operator can promptly make the necessary adjustments.

#4

Operator Safety

The probability of a gas leak increases with the number of possible leak paths. Gas leaks can expose plant operator to the risk of catastrophic equipment failure which may cause injury or even fatal accidents.

The integral design of the customized sampling valve reduces the number of possible leak paths and hence reduces the risk of a leak.

#5

Environmental safety

A representative sampling system based on AS-Schneider sampling valves also helps ensure environmental safety by reducing the risk of environmental leaks.

Conclusion

A representative sampling system offers major benefits to natural gas plant operators. Setting up a reliable gas sampling system has traditionally presented several challenges.

The customized sampling valve simplifies installation of a representative sampling system. It has a looping design which allows it to be used with measuring devices that require looping gas flow.