EJMA Section 4.10.2 provides an empirically derived formula for internal sleeve thickness as follows:
tmin = t(based on diameter) x (V/100ft/s)^2 x (L/18")^2 x E300F/Etemp
where:
t is .06" for 26" to 48" diameter (my particular case)
V is fluid velocity if greater than 100 ft/s
L is length if...
thread238-153684
A 50 ft dia x 34 ft high aluminum demineralized water storage tank located outdoors began leaking from the floor at a single location on the perimeter in March.
After draining, internal inspection revealed a 1/2"dia hole in the floor plate approximately 6 inches inboard from...
Has anyone connected a tandem reservoir extension (TRE) to a constant level oiler (CLO) on a particularly leaky motor bearing reservoir?
1 USgal CLO units are available but vibration of the cantilevered mass and frequent top-up requirements produce cover and threaded cap seal leaks that result...
With reference to thread124-450268, LP examination of the 17-7PH or S301 knife blade ends has revealed unusual mind-plane cracking (see pictures on word document attached).
Is it possible that surface hardening heat treatment created layers having different Modulus of Elasticity (E) and thermal...
Would the following iterative calculation provide a reasonable estimate of pump rundown time?
The hydraulic system P vs Q relationship is:
PT = PS/QS^2 * QT^2
PS = operating pressure at start of rundown
QS = operating flow at start of rundown
QT = flow at time T
PT = pressure at time T
Flow...
The diaphragm has separated from the stem inside a weir type diaphragm valve in vacuum service.
The process vacuum is holding the diaphragm in the closed position, which appears to be intact because it is not passing.
If the bonnet was drilled and tapped for a fitting and attached to a vacuum...
At my plant, peening is used to temporarily stop leaks on pressurized metal items.
This includes the following applications:
- closing through-wall cracks & pinholes on pipes
- closing gaps between mating pipe flanges or body/bonnet flanges on valves
- sealing interface gaps between tongue...
At my plant, peening is used to temporarily stop leaks on pressurized metal items.
This includes the following applications:
- closing through-wall cracks & pinholes on pipes
- closing gaps between mating pipe flanges or body/bonnet flanges on valves
- sealing interface gaps between tongue and...
If condensation is boiled off above 212 degF when bolted joints in steam service are placed in service, is propagation of existing cracks in A193 B7 studs arrested?
Assume there is enough gross stud cross section left to ensure elastic response to stud preload and transient thermal loads as the...
Does anyone have experience with cracking of the X knife blade assembly on reverse buckling, large (>24"dia) rupture disk designs in saturated steam service?
The blade ends are fillet welded to the inside wall of the disk holder and the cracks appear parallel to and 1/4" away from the fillet...
thread378-336794
I am looking for a recommendation for a laboratory that performs viscosity testing of valve packing sealants that are very viscous, require high pressures to flow and likely non-Newtonian.
The intent is to predict whether control valve response will change due to viscous drag...
The continuous boiler blow-off system at our plant discharges a constant mass flow of 0.2 kg/s at 6 psig into a lake via 250' of buried 6"nps pipe with a 12:1 drainage slope.
At the lake surface the 6"nps pipe branches into three 3"nps pipes that drop 14' vertically below the lake surface where...
At our plant, 1/2"nps bypass valves are 'stayed' with brackets fillet welded to the body flanges of their 14"nps boiler feedwater valves.
Fatigue failures of the bracket welds has called for beefing up the bracket configuration and weld design to avoid resonance.
The legitimacy of the...
Two poppet check valves have the same Cv but different cracking pressures.
Does the lower cracking pressure result in lower opening response time?
We would like to reduce opening time of a solenoid valve handling air that has a poppet check valve downstream.
The Cv is acceptable for steady...
thread238-9659
The manufacturer's manual for their 30 year old power transformer infers that the micarta diaphragm and goose neck vent protects the gas detector relay from seeing pressure transients above 5 psig, which will cause loss of calibration. It also credits the diaphragm with...
Does anyone know how to determine the maximum design pressure criteria for valve stuffing boxes and what factor of safety is available for packing compression?
Welders in my plant contend that 40 year old sections of austenitic grade 316 stainless pipe that have carried FRF at 1350 psig and 140 degF cannot be cut out and re-welded because residual FRF cannot be completely driven from the microstructure and contaminates the weld.
I can't find any...
Phased Array inspection of a wrought A234 WPB, 18"nps sch 40, 90 degree, LR elbow has revealed laminations and inclusions.
The majority are located mid thickness along the cheeks of the elbow, not the extrados or intrados.
The majority lie parallel to the surface and do not break through...
At our plant, external examination of a section of A312TP304L boiler blowdown pipe detected the onset of stress corrosion cracking.
Is there anything that can be done to arrest this cracking mechanism or is whole sale replacement the only option?
In my plant there is an ancient upside-down bubbler system that provides level indication for a large tank (bubbler schematic attached).
A constant flow regulator pushes helium 25’ down to a reservoir/valve (drawing attached), which then bubbles it through 45’ of 1”nps drain pipe located in the...
