Thanks for your replies, particularly Metengr. He is correct that we do lower pressure air tests to look for leaks when a boiler is offline for several reasons. The reheater sections are dry and it is extremely inconvenient to fill them with water due to isolation and pipe loading constraints...
Is there a maximum test pressure allowed for pressurizing a boiler with air to look for leaks in power boilers? I don't see one in the boiler code. We try to limit pressure due to stored energy.
It sounds to me like you are just looking for an automatic vent valve. If you search the internet you will find them readily available. Are you after something more specific? If so, you need to include more detail with your question.
Look at ball joint assemblies. McMaster-Carr for example carries a variety of small inexpensive ball joints which are a ball on a small bolt some of which can be easily separated if necessary. Small joints are $1 or $2.
We have a generator seal oil system where the seal oil runs through a vacuum tank which in turn supplies suction to the seal oil pump. The tank has severe foaming problems if we attempt to increase the tank vacuum to normal operating levels. Water in the oil does not appear to be the problem...
Thanks Kwartha,
We were already talking to Sulzer. I had not approached the others on your list though. Our experiences with Flowserve have not been positive in recent years so they are only used as a last resort. They may have satisfactory pumps but their sales and service/parts...
We have utility boilers where oil is supplied to the burners and part is recirced back through a "constant differential pump" which controls the differential across the burner tips. This is a multistage centrifugal pump. The biggest ones we have are 440 GPM and 760 ft head. They pump...
I would say you are correct as far as gimbal forces from pressure go. You may need to consider bending loads on the expansion joint itself if it is large enough or stiff enough to be significant. Make sure you stay within the flexibility limits of the expansion joint (bellows?)itself as well...
KRB, Thanks for your reply. You say to consult a duct design manual. Can you give me a reference? I have the ASHRAE fundamentals handbook but was looking for something more specific and preferably something that speaks to design of turning vanes in large ducts. Are they just arbitrarily...
Does anyone have a good reference book on large duct design specifically with regard to expected pressure drops in fittings and design and benefits of turning vanes? I am looking at large (20' square)power plant exhaust duct and would like to know if I could reduce pressure drop significantly...
