The Pre-Expansion Guide: Steps & Tools

Shell and tube exchanger

It’s no secret that tube leaks or failing hydro is a huge headache for organizations. When it comes to tube installation, proper expansion can be the difference between an expensive repair bill and a long-lasting vessel.

In this article, we’ll explore the fundamental steps that should take place before tube expanding to ensure you get the best results. We’ll also look at some tools you need to complete the job safely and efficiently.

Are You Familiar With The Pre-Expansion Steps?

Preparation of Tube Sheet Holes: Heat exchangers / Condensers

Here’s what you should do to prepare the tube sheet holes in a heat exchanger or condenser before expanding. 

  1. Drill and ream tube sheet holes to TEMA or ASME codes.
  2. Ensure the tube sheet material and ligaments are adequate for a secure and permanent tube to joint.
  3. If applicable, use a sizing or burnishing tool to ensure that the tube hole has a smooth finish. The ligament’s tensile strength will increase as well.
  4. The tube’s joint strength is determined by the type of serrations or grooves used. When retubing, cleaning out any metal or foreign material from the grooves is critical.

Preparation of Tube Sheet Holes – Drums / Tube Sheets / Headers

Here’s how you prepare tube holes in drums, tube sheets, and headers for tube expansion:

  1. Tube holes should be drilled or reamed to comply with API, ASME, or National Board Inspection Code 
  2. It’s critical to avoid longitudinal scratches or cracks in the tube seat during this procedure.
  3. Pre-rolling of tube holes is necessary in cases where out-of-roundness is severe.
  4. Before tubes are inserted, clean the tube walls and grooves in the tube walls down to the bare metal. Oil, grease, rust, or dirt from outside should all be removed. 

After tube holes have been prepared, they’re often coated with a rust prevention compound. Before inserting tubes it’s important that any traces of coating be removed.

Which Tools Will You Need For The Pre-Expansion Process?

You’ll need the following heat exchanger or boiler tools for the pre-expansion process:

Tube Hole Gauges

Tube hole gauges allow you to accurately measure tube IDs and tube sheet holes, making it much easier than ever to make a mechanical joint. Proper mechanical joints ensure the efficiency and safety of the vessel.

Tube Sheet Hole Brush

It’s vital to clean the tube hole surfaces before rolling. You can clean the tube sheet hole ID with a tube sheet hole brush to help minimize the possibility of leak paths during expansion.

Grooving / Serrating Tool

Grooving (serrating tools) can be used with milling or drilling equipment to prepare tube sheet holes. These tools produce uniform diameter and depth grooves in the machined tube sheet hole production.

Tube Pilots / Guides

Tube Pilots (Guides) guide new tubes through tube sheets and tube sheet support plates that may be found in heat exchangers or surface condensers. The tube guide head has a shoulder for the tube to rest against, preventing it from being bent as the guide passes through the support plates.

Tube Gauge

Tube Hole Gauge

Find Your Tube Expansion Tools At Elliott Tool Technologies

If you’re looking for quality tube expansion tools, look no further than Elliott Tool Technologies. We offer all the tools you need for tube expansion in heat exchangers and boilers. Our team represents 125 years of manufacturing, sales, and engineering experience.

Whether you’re looking for tube installation tools or for other tube tool maintenance products, we’ve got a wide catalog for you to choose from. Don’t hesitate to get in touch with one of our representatives. We’ll help you find what you need to keep your business running smoothly.

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