In line with what dave2109 stated, we use a small orifice in check valves in some limited applications to keep the water in the pipeline flowing (slightly) for freeze protection...
Another item to look at is how frequently and how many times these bolts have been torqued (and how much torque is involved) -- the metallurgical analysis mentioned by artisi should point to the cause -- saxon's comments should be considered by all...
Thanks, BJC -- have used these in the past but due to the local economy, many of these are no longer available in the near region -- but I still converse with our vendors and remind them to inform me of anything in the area (radius of 200 to 300 miles)... thanks for the response..
Thanks, guys
I have looked at those sites referenced by the licensure boards and am currently using some of those (T2G has some that is relatively inexpensive in comparison to others). {A couple of states limit on-line training, so I must tailor my CE to meet those requirements now also)...
With all due respect,Accystan is correct -- I have used the wrong conversion factor (ounces/sq.in.)
My error -- glad that Accystan was watching -- as he points out the correct factor is 1" H2O = 0.0361 psi
(and my rule of thumb deals with inches Hg, not inches H2O)
My apoplogies...
I agree in concept -- I should have left off the "g", my error (or added 'wg' to my answer) -- however, the question dealt with inches water gauge which is also a measurement above atmopheric pressure therefor the value is still valid if you disregard my error in units...
inches wg refers to inches water gauge -- and I am assuming that you mean psi (pounds per sq in) when refering to a pound of gas: use the standard formula 1" H20 = 0.5781 psi (when estimating I usually use a rule of thumb that 1" H20 is roughly equivalent to ½ psi -- recognizing that...
I have always seen and always used "keyed-alike" locks for such installations (I live in USA) -- in the field, we never knew ahead of time which technician, meterman, or substaion member whould be assigned to work on the equipment, and during storms, any number of people had to have...
I not familiar with your application but we have used split range controllers to control separate valves in power plants that will have the same ranges you refer to... as you allude to and others point out, you want the operation of these valves to be dependent upon each other, not independent...
What did you do with the unused pair? Typically, I will also ground any unused pairs at the same end as the shield is grounded (don't know if that helps any, it's just a practice I have always done...) Don't have a lot of experience in handling the rough environment you have, so I can't...
After a turbine overhaul is tough -- verify that the shells had been blued and you had good surface contact before torquing the studs... make sure the steam seals are working properly, check the lead diaphram to make sure it wasn't cracked or slightly cut by the knife edges, make sure the...
Breakers for motor loads are usually sized differently from other loads -- you need to know what load the breaker is serving....
As DanDel poins out the NEC specifies several procedures... take the time to review these...
I think Doug and TomG -- the motor's feet are either "ground" or machined to form a flat plane -- if you hand grind one foot, you can not maintain that same plane and shimming will not provide an even distribution on the foot and alignment will not be consistant...
As I recall, this is typical of an ID fan driven by a VFD...
The VFD will start the fan and gradually come up to (as dictated by control program) speed --the motor starting current and initial air flow are significantly reduced compared to the non-VFD starting methods...
