TPi May 2016

Inconel 625 cladded and dispatched in a few days. I’m proud to say we were able to support a field operator directly at a time they needed it most.”

temperature service are ASTM A105 carbon steel. In low temperature applications, materials such as A350 LF2 could be generally used. In other working environments, ones of a corrosive or high(er) pressure nature, a standard such as ASTM A182 (which covers a wide range of ferritic/austenitic materials) could be applied. Case study #1 – 18" Class 900 flange, 625 clad, fast turn-around, Australasian customer A leading Western Australian operator had a requirement that was holding up a major project. A solution was needed in the shortest possible time for a gas field that lay in up to 70m of water. An 18" ANSI B16.5, Class 900, RTJ, ASTM A694 F65 weld neck flange needed to be manufactured to a bespoke drawing, pre-machined out, Inconel 625 cladded, finish machined and shipped out with a full certification pack – all within three days. The flange had such project implications, the client flew in from Australia to see first-hand the work in production. Neil Brown, Alexander Comley’s works manager, commented, “Our customer’s project deadline was significant enough for them to fly from Australia to witness the manufacturing process here. With the team here we manufactured, had

Tubesheet flanges for shell and tube heat exchangers One of the most common heat exchangers in service within industrial process applications is the shell and tube heat exchanger. They are available in many shapes and sizes, and have been used in industry for over 150 years. In this exchanger group are various sub design types: fixed, U-tube and floating tubesheet. Variations of all can be denoted as type E, F, G, H, J, K or X. The main applications are where high pressure/temperatures are key considerations. Loosely, general designs consist of an outer shell in which resides a tube bundle (these can be configured as finned, plain, etc), sealed at each end by a tubesheet that isolates the tubes and the outer shell. Shell and tube heat exchangers have the capability to transfer large amounts of heat at low(er) costs. This, in principle, is down to both design simplicity and effectiveness – a large tube surface for reduced weight, volume of liquid and floor space. Whilst there is a wide variety to choose from, there are certain key components similar in all tubesheet flanges (‘tubesheets’). Tubesheets have tubes attached to them within the body or ‘shell’ of the heat exchanger. The tubes allow the movement of a given medium (gas/fluid) through the shell chamber, stopping it mixing with a second fluid medium that lies outside these tubes. As long as there is a temperature difference between these, in effect, the two flow past one another exchanging heat without ever mixing. Tubesheets can be fixed or floating, dependent on the application the heat exchanger is designed for. Tubesheets are a critical component. There are a multitude of materials they can be manufactured from. Material selection is made after careful consideration, as it is in contact with both fluids. It must therefore have the necessary corrosion

24" 1,500lb RFWN flanges, material F60, readied for client

Large diameter flange, mid-manufacture on the Doosan VTS1620M VMC machine

Tubesheet, 1,800mm Ø, 35mm thick, on machine bed, 2,220+ holes

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May 2016 Tube Products International