What is the rational of using SS304L fittings in Cooling water service, where the pressure is not very high? 212DegC (100DegC) is high enough to cause Cl related issue for SS300 series alloys. In my opinion CS fittings are good option for water service at low pressure and moderate temperature.
I have not seen a Spiral wound gasket in Heat Exchanger services as all the Spiral wound gaskets are now changed to kamprofile gaskets with thinner width. Kamprofile gasket seems to accommodate more seating stresses as they are used for seating stresses of 10ksi-40 ksi with a optimum of 25ksi...
Under severe corrosive conditions Seamless piping is used. Seamless piping is also a preferred option under High Pressure, high temperature, cyclic services. ASME code B31.3 does not specifically provides a guideline to select between Seamless and ERW piping but considering the joint efficiency...
Creep is time dependent failure mode, which will depend upon high temperature and applied stress. As per API - 571 the recommended temperature above which creep failure becomes a concern are as below
Carbon Steel ( UTS<60 ksi) Temperature limit is 343 Deg C
Carbon Steel ( UTS>60 ksi)...
Gasket selection normally depends upon flange calculations and required gasket seating stresses. Normally for Kamprofile gaskets the seating stresses are within 10ksi - 40ksi and optimum will be 25ksi. Similarly for Spiral wound gaskets the maximum seating stresses are 25ksi and the optimum will...
Hi Asisraja,
Normally the line thickness is not considered independently but in conjunction with Flange ratings. Most of the organizations have the line classes based on pressure and temperature ratings and then line classes are specified. For your case at design temperature of 200 Deg C and...
Hi Asisraja,
Selection of piping thickness is not taken independently and in done in conjunction with the Flange ratings. Most of the organizations have the Piping classes, where depending upon the Pressure and temperature piping Schedule is decided. For your given conditions of Design Pressure...
Looking into the difference between P9 and P91 material, addition of around 0.18-0.25% Vanadium is done to P91 material to provide higher Tensile and Yield Strength.
P9 P91
Tensile strength (ksi) 60 ksi 85 kis
Yield...
In order to stop galvanic corrosion happening between CS and SS flanges, Flange Isolation Kit is used. This kit looks like following. This kit is also used providing Isolation to Cathodic Protection between an underground section to Above Ground section.
As per ASME Sec IX P22 material falls under P no. 5A and Gr. No. -1.
Looking ASME Sec VIII Div-II Table UCS, Normal holding temperature for PWHT is 675 Deg C with holding time as 1hr/inch with a minimum of 15 minutes.
As per SA-312 specification, the Practice A262 requires the test to be performed on sensitized specimens in the low Carbon and stabilized types and on specimens representatives of the as -shipped conditions for other types.
What does that statement means:
Does it mean that for low carbon and...
Under high aggressive corrosive situation use of Inconel 625 seems better than Inconel 825 as Inconel 625 offers better pitting resistance than Inconel - 625. We have also used Haste Alloy C-276 in extreme Sour water service at high temperature.
In Refinery FCCU operation, SS304H material is used for cyclones and operating temperature remains high as 730 Deg C. At this temperature SS-304H suffers Sigma phase embrittlement and loses low temperature toughness. High temperature exposure of SS-304H produces Sigma phase and that shall be...
Hi,
I am doing RBI on Boiler Steam Drum. Consequence category states Burst as one of the consequences. Our RBI system does not calculate the Burst calculation and does not give any output. I am planning to run Burst Calculation and need some help in calculation. Is there any literature where I...
It is a good practice to Overhaul and Recalibrate the Pressure Safety Valves with the equipment shutdown. This will give an opportunity and confidence in maintaining the Plant safety devices in functional order. API-510 is a good code to refer for all Inspection activities but a risk assessment...
In Refinery we are using Old Boilers made in 1965 with a Design Pressure of 4830 Kpa and Design Temperature of 371 Deg C. Steam drum thickness is 66.7mm where as Muddrum thickness is 51mm. This is high Pressure Boiler used at 4100 Kpa steam. I am doing RBI for Steam Drum and Mud Drum but their...
