Posts Tagged ‘boiler’
I have been asked over the years “What is a boiler horsepower” and what is the design criterion of square feet of heating surface per boiler horsepower.
We have written many articles about flame safe guard controls on Control Trends but we have not really given an explanation on the basic principles of these controls.
Proper boiler blowdown is an essential part of firetube boiler operating proceedures. It is necessary to control the amount of TDS (total dissolved solids) in the boiler water.The total TDS should not exceed 3500 parts per million in a scotch marine boiler. If the blowdown is not controlled, excessive dissolved solids will have a tendency to increase and concentrate to a point that will cause a foaming or a carry over condition which will contaminate the steam.
The following is a list of what causes a LWCO switch to malfunction taken from the McDonnell & Miller Service Guide.
Honeywell Burner Boiler Flame Safeguard Training Classes
Questions have been asked about the proper mounting of a Low Water Cutoff on a steam boiler.
Notice: The measurements given in this article will be close to the measurements necessary for the installation and may not be the same as the recommended measurements by the boiler manufacturer or the manufacture of the Low Water Cutoff. Care MUST be taken to follow installation measurements supplied by the manufacture of the boiler and control.
The first issue to answer is…Is this installation for a primary or secondary LWCO? The Primary LWCO is the operating LWCO and the Secondary LWCO usually incorporates a manual reset and is used for a safety backup for the primary.
Note: on a steam boiler please make sure you have a set of water gauge cocks in the installation. The “center line” of the visible glass should correspond with the boiler’s COLD WATER LINE.
The next issue for the service person to identify is the location of the COLD WATER LINE on the boiler. This is the “normal” cold water fill line as established by the boiler manufacturer. After the boiler’s cold water line is located, look at the LWCO and locate the level mark on the body of the LWCO. With these two marks established installation can now begin.
Primary LWCO Installation:
As a primary LWCO the level mark of the LWCO should be placed for mounting between 1 3/8” to 1 ½” below the boiler’s cold water line which will establish the boiler’s normal operating range.
½” to 3/8” below the LWCO’s level mark will be the burner’s “cut-off level”
Secondary Safety LWCO:
As a secondary safety LWCO the level mark of the control should be placed for mounting between the 1” to 1 ½”area below the primary LWCO’s burner cut-off level. Careful attention MUST be made not to let the float drop below the lowest visible level of the site glass.
Before commissioning the boiler for final usage PLEASE test the Primary and Seconday LWCO levels and make adjustments as needed for proper levels.
I would like to thank Peerless Boilers for their help with information and drawings supplied in this article.
So you might be asking why are we doing three different posts on Testo Combustion Analyzers ? The main reason is that we have three different videos on the Testo Combustion Analyzers, and I did not want to put them all in one post. The first video focuses on combustion testing, the second video on the Testo 327 combustion analyzer, and this post highlights the Testo 330 combustion analyzer.
As you can see the Testo 327 and Testo 330 are very similar, with the main difference being Read More
Of all the combustion analyzers we handle, which include great combustion analyzers by Bacharach and UEI, I love the Testo Products. Testo Instruments is a world leader in combustion and HVAC measurement equipment. The design of all the Testo products is well thought out and engineered; Testo’s quality is unsurpassed. Check out this video by Value Testers Jim Bergnann to get an idea of what I am talking about.
As you can see the Testo 327 combustion analyzer has a lot of great features that an HVAC technician needs when working with combustion equipment. But is it the right tool for you? Read More
This Fall Testo is offering a $200 rebate on its 327 and 330 Combustion Analyzer kits, so if you’re in the market for a combustion analyzer now would be a good time to get one. If you purchase a kit between now and December 15, 2010, you will receive a $200 rebate on a great quality product.
The Testo 327 Oxygen Analyzer quickly measures and makes better O2 adjustments with its simple, intuitive operations. The pre-calibrated sensors use the most modern materials and come backed with a 3-year warranty. Read More
Over the years I have been asked how to properly pipe a steam heat exchanger. I developed the drawing below to help answer this question. There are other piping additions that can be added according to your needs, and this drawing does not cover all the additions but should serve as a good workable starting point. A few points to remember…1. A vacuum breaker and/or vent should be installed…. 2. The steam trap should be properly sized for the amount of the pounds per hour steam capacity of the heat exchanger, and the trap should be sized for the pressure at the trap not for the inlet pressure of the control valve…3. A properly sized relief valve must be installed on the hot water outlet side to protect the heat exchanger from possible damage due to volumetric expansion.
I hope this answers some questions you may have. If you need more answers please call Stromquist and Company at 1-800-241-9471, and we would be happy to finalize an answer for you.
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