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Hi gents Thank you for you replies Please see below for a more detailed sketch. The plate heat exchanger has an attemporation loop since it's for a pasteuriser, where strict temp control is required. I have snipped a 3d of the piping below. We're talking 51-101 mm (2-4") dairy tube so not...

Hi Lilliput1 Thank you for your reply, Apologies as I should have been more clear, I'm aware that the header tanks acts both as a top up and relief (since it is vented). And yes the closed loop would have an expansion vessel, thermal relief and pressure reducing valve. I just didn't want to...

- Minimise threaded fittings - Use single body/piece valves I think there's a bit of a trade-off between leak possibility and maintainability

Hi I have searched the forum but couldn't find a question quite like mine. If this has been discussed before my apologies The closed loop consists of a tubular heat exchanger (for heating the hot water) and a plate heat exchanger (for exchanging heat to another fluid). The heat exchangers are...

Hi I did a quick check, for 125 to 80 psig superheat is about 6 degrees C but this assumes 100% dry 125 psig steam, which is practically impossible. Even with a separator upstream of your PRV, you won't have 100% dry steam. See for yourself the effect of 99 or 98% dryness on the isenthalpic...

I think you have a couple options 1) 3 way ball valve with upstream pressure switch 2) Relief valve set at desired pressure. When low or no pressure, no flow to your house. Still requires separate flush/drain and still a risk that once pressure returns, it'll flush dirt downstream 3) Might be...

Thanks for your reply gerhardl, you're correct that all valves will have problems without proper condensate separation and trapping. The valves are to be installed on shell and tube heaters (10 barg) with a single separator upstream. Lines will be taken off the top of the header etc. MFJewell...

Hi The customer's maintenance engineer is requesting manual ball valves for manual steam isolation (double block and bleed). I have used gate and globe type (Spirax Bellows Seal) in the past with good result. I prefer ball valves as automatic steam isolations. Something like a Keystone KTM...

Hi gents Cost is not much of an issue and the valve sizes are typically < 100 NB so not huge. We use bypasses to handle the large turndowns required in dairy plants. The connecting pipework is carbon steel including the flanges, valves etc. Line traps are typically thermodynamic stainless steel...

Hello What are your thoughts on globe control valve body material choice for high pressure steam? The supply pressure is 41.5 barg 254C design and typically 37 barg saturated operating, which is dropped down to 10 barg for distribution to heat exchangers, process vessels etc. The control valve...

The following topics might be of interest as refreshers: - Process control (basic PID, master-slave logic etc.) - Process quality (engineering statistics) - Basic fluid and thermodynamics (Bernoulli equation, pump basics, q=mcpdT) - Simple chemistry (exothermic/endothermic, equilibrium...

Thanks apetri you're right i think i can't solve this simply. I work in dairy, food and beverage not chemical or petrochem so don't readily have access to chemical simulation software but I'll let you know if I get further

Hi :) I had a go at the thermal calc due to expansion by Prex (faq378-1339) however I would also like to look at calculating the pressure rise due to nitric acid decomposing into gases (NO2, O2) in a shut in pipe eg. between 2 valves. I do not believe I have the thermodynamics set up correctly...