Recall that this API 600 requirement is for a wedge gate valve. As the name implies, a wedging force is used to accomplish sealing. To accomplish the minimum seating force for sealing, the disc must be pushed down beyond the point at which the two seating surfaces come in contact. Therefore, the...
The standard torque equation is T=KFD where T = torque, K is the "nut factor," determined experimentally, F is the force (LBS, N) and D = the nominal bolt diameter.
Does anyone have any data/experience with the value of K for 300 series bolt material, e.g., A193-B8? As received values (dry)...
The drop in pressure drop before reclosing is called blowdown. For a ASME Section VIII (UV Stamp) valve it should be about 7% of the set pressure or 3 psid whichever is greater. For you then it should be 5 psid. Your blowdown is about 50%. For a safety valve, blowdown is usually adjustable...
Suction systems are more effective in general compartment cooling. If you plan to use the same air flow to cool other components then suction is good because of the issues brought up by pjhype. Also the fan motor add heat to the flow. With suction the heat goes away. This also means that with...
B16.5a-1998 Paragraph 8.3, Hydrostatic Shell Test, states:
"The hydrostatic shell test for flanged fittings shall be no less than 1.5 times the 100F rating rounded off to the next higher 25 psi increment."
This says that the manufacturer has tested them at 1.5 times 100F rating. You...
Are all 30 machines the same and do they do the same thing?
If so, then average is
(total hours for all 30 machines for 350 days)/(30 x 350).
If all the machines don't do the same thing then you have to classify your data by purpose and treat each classification separately.
From Fried and Idelchik
"Flow Resistance: A Design Guide for Engineers"
Taylor & Francis 1989
Paragraph 2-1, p. 5
"It should be noted that the concept of hydraulic diameter will provide values of pressure losses of acceptable engineering accuracy for most shapes, where there are...
Here is what I think you are asking:
You have 30 machines. You have 350 days of data for each machine. You want to know the most likely period of time each machine will work.
My initial thoughts:
The most likely period of time will simply be the mean number of hours of operation for each...
As far as B31.1 is concerned, there is no explicit restriction on the use of Sched 20 (I don't believe there is a 20S). The pipe wall must not only meet the minimum thickness requirements for pressure but also the thermal expansion, weight (dead, full of fluid), other sustained loads (i.e...
In 1981 I used Harwood Engineering in Walpole, MA for test rig valves/fittings/tubing to test API valves at 30,000 psi shell and 20,000 seat. The test rig itself we designed to 30,000 psi and hydroed to 45,000 psi. We were very satisfied with their performance. Their url is...
Also look at the following web pages. The hardened versions have problems with age embrittlement above 600F.
www.framatech.com/pdf/17-4PH-Xu-2554.pdf
www.nrc.gov/reading-rm/doc-collections/gen-comm/info-notices/1992/in92060.html
Nuclear power plants require a controlled method for making up all joints. For most joints this means using a calibrated torque wrench, as well as a specified sequence for tightening the bolts. There are reasons for this ostensibly crazy approach but they would take too long to explain.
As for...
See Thread 408-21855 for discussion of Class. Allowable pressures are directly related to the class number, e.g., a Class 600 valve can operate at twice the pressure as a Class 300 for a given temperature/material. However, this relationship does not apply to Class 150. See ASME B16.34 Annex F...
