How to Measure
Below is a step-by-step description of all the component parts of a tube bundle that are required for duplication. Please note the corresponding component numbers on the drawing on page six.
- "D" BUNDLE DIAMETER - This is the overall diameter required to fit the bundle in an existing shell or tank. This dimension includes any baffles or tube supports. A good way to get an accurate "D" diameter to measure the circumference and divide by 3.14. This gives you the diameter of the bundle.
- "OAL" - OVERALL LENGTH - Measured from the face of the tubesheet over the entire length to include the last bend.
- "T" - TUBESHEET THICKNESS - Tubesheet thickness varies from 5/8" to 3" thick.
- "TSD" - TUBESHEET DIAMETER - The tubesheet diameter is always larger than the "D" dimension or bundle diameter.
- - 6. - 7. BOLT HOLES - Some tubesheets have bolt holes and some do not. Often the bolts that go through the head and shell bypass the tubesheet - that is the bolts go around the tubesheet and not through it. In this case there is no bolt hole pattern and 5-6-7 are not applicable. The tubesheet is boltless.
- NUMBER BAFFLES - Please see not on page six.
- BAFFLE SPACING - Distance between baffles or tube supports if there are tube supports in lieu of baffles.
- TUBE DIAMETER - Typical tube diameters are 3/8", 1/2", 5/8", 3/4", 1 1/4" O.D.. Most steam converters and water/water exchangers are 3/4" O.D.. Please note that 3/4" O.D. tubes have approximately 5/8" I.D.s . Some tank heater bundles have 1 1/4" O.D. tubes.
- TUBE MATERIALS - Most HVAC exchangers have copper tubes and these are easy to identify. There are alternate tube materials available if you need them. Some examples are: 90/10 or 70/30 cupro-nickle, carbon steel, stainless steel, carpenter 20 or exotic materials like titanium.
- TUBE THICKNESS - Most 3/4" O.D. copper tubes are 18 GA and most 1 1/4" O.D. copper tubes are 16 GA. USA recommends and uses 16 GA for both O.D.s. Heavier walls are available if required.
- STRAIGHT TUBES - Some bundles have tubesheets at both ends and there are straight tubes between. Count the number of Straight tubes.
- "U" TUBES - Most replacement bundles are "U" tube type. Count the number of complete "U"s.
- SHELL or SLEEVE DIAMETER - Specify the O.D. or I.D. of the unit that the bundle will slide into. What we are really interested in identifying is the space available to slide the bundle into.
- TUBE PASSES - Look at the tubesheet to identify the number of passes the liquid or steam makes through the tubes. Most bundles are 2 pass, but can be 4 or 6 pass also.
- TUBESHEET MATERIAL - Most tubesheets are carbon steel, because this is the most economical material available. Alternate materials are: stainless steel, carpenter 20, titanium, copper faced steel or brass.
"U" Tube Bundle Information
How to Measure