Steps to Consider Before Rolling Tubes
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.
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.
Drill and ream tube sheet holes to TEMA or ASME codes.
Ensure the tube sheet material and ligaments are adequate for a secure and permanent tube to joint.
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.
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:
Tube holes should be drilled or reamed to comply with API, ASME, or National Board Inspection Code
It’s critical to avoid longitudinal scratches or cracks in the tube seat during this procedure.
Pre-rolling of tube holes is necessary in cases where out-of-roundness is severe.
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.
Contact Gulf States Industrial for all your tube tool needs to retube heat exchangers, chillers and boilers.