MGT Consulting Network Blog

The course notes for Shell and Tube Heat Exchangers-Mechanical Aspects have been updated. Viewers should be aware that these notes are based upon Stanley Yokell’s book, “A Working Guide to Shell-and-Tube Heat Exchangers”, McGraw-Hill 1990, now out of print and available only on the used book market.

We have available a CD with 50 annotated photographs of feedwater heater failures and autopsies. We will provide them as a bonus to purchasers of our Closed Feedwater Heater Suite. They are also available for separate purchase for a price of $100.

As of today, MGT Inc.’s copyrighted Closed Feedwater Heater Suite is updated. The current price is $590. We will provide purchasers with a bonus DVD showing the installation of a feedwater heater bundle in the shell during manufacture.

MGT’s course, “Closed Feedwater Heaters-Mechanical Aspects” has been updated to August 2010. MGT’s courses, “Power Plant Auxiliary Shell-and-Tube Heat Exchangers
and Closed Feedwater Heaters” and “Shell-and-Tube Heat Exchangers, Mechanical Aspets” are in process of updating. The update of our course, “Tubular Exchanger Inspection, Maintenance and Repair” will follow.

For the closed feedwater heater and the Power Plant Auxiliary Shell-and-Tube Heat Excangers & Closed Feedwater Heaters, we are currently including a bonus DVD that illustrates the insertion of a feedwater heater bundle in the shell.

Stanley Yokell’s paper on hydrostatic testing feedwater heaters and auxiliary heat exchangers Paper No. 2010 – 27106 has been accepted for presentation at the July PowerGen conference in Chicago. The paper demonstrates that pressure gage divisions of typical gages used in hydrostatic testing are too coarse to disclose minute leaks such as weeping from the channel through the tube-to-tubesheet joints during the half-hour TEMA-required hydrostatic test time hold time.

The paper uses as an example testing a U-tube, closed feedwater heater at 4600 psi and a leak volume of 10 drops of water over the half-hour hold time. It shows that the change in pressure resulting from such a leak would be so small that it would not register on the test gage that would typically have 50 Psi graduations.

In most feedwater heater designs and in some auxiliary tubular equipment, the back side of the tubesheet cannot be visually inspected. Because the hydrostatic testing does not disclose minute leaks such as weeping, defined as 10 drops over the half-hour test hold time, Purchasers are advised to require Manufacturers to perform leak tests described in the ASME Code’s section V. As a bare minimum Purchaser’s should require the Manufacturer to perform a Gas-Bubble test. However, it is more preferable to perform both the Gas-Bubble test and a Helium sniffer leak test (mass spectrometer leak test).

Chemical Engineering Magazine’s April 2101 Feature Report is Stanley Yokell’s article, “Full Length Sleeving for Process Heat Exchanger tubes.”

Stan Yokell is now a Life Member of the American Society of Mechanical Engineers (ASME) and the American Welding Society (AWS)

A new post on the MGT Blog at http://syokell.blogspot.com/ discusses hydrostatic testing heat exchangers, with emphasis on testing when leaks are not visible as in fixed tubesheet designs and typical closed feedwater heater construction. It discusses weeping from the channel side to the shell side and points out that the gages customarily used in heat exchanger shops to determine whether there is leakage from the channel to the shell through the tube-to-tubesheet joints by pressure loss are inadequate for indicating weeping. The post on the blog poses questions about the ASME Code’s requirements and suggests cautions that Users, Designers and Manufacturers should take for constructions in which leakage is not visible.

MGT Inc., which has made hundreds of presentations in-plant and at public offerings of our courses, “Shell-and-Tube Heat Exchangers – Mechanical Aspects”, Closed Feedwater Heaters – Mechanical Aspects”, “Tubular Exchanger Inspection, Maintenance and Repairs”, “Tube-to-Tubesheet Joints”, and “Power Plant Heat Exchangers”, is no longer presenting these courses. However, these courses are available for sale on CDs with Power Point presentations and complete course notes in PDF format. This are accompanied by DVDs with videos that illustrate the material. Please see http://www.mgt-inc.com/products_services/ for pricing and availability.