Legal Requirements for water heaters in EU/UK

[youngengineerpl]

Hello,

I have been design engineer for 2 years only. So I am just at very begining of my trip.
So far, I have had chance to participate in designing the pressure vessels in accordance with ASME sec. VIII, div I.
As you can see my experiences are not stunning.
Last week I was asked to get some informations about European standards of design of pressure vessels. The purpose is to find out which of
legal requirements have to be met to design indirect potable water heater (just stainless steel tank in insullation) which destiny is UK
market. Design of considered water heater is very simply: cylindrical shell with coil inside, shell enclosed with cylidnrical heads on both sides.
300l of volume, 3 or 4bars of working pressure, 100-110 C of working temperature. Everything enclosed in thermal insulation (optional).
So far I have found the following:
- ecodesign requirements for water heaters and hot water storage tanks, Regulation (EU) No 814/2013
- the energy labelling of water heaters, hot water storage tanks and packages of water heater and solar device Text with EEA relevance, Regulation (EU) No 814/2013

Both above are just requirements which refer to energetical aspects of design. What about strengh design aspects though?
I guess I should consider PED 2014/68/EU. But on which part of this regulation I should focus most? Are there any different reguations that I shoud consider?
Of course I am not waiting for ready solutions just for some tips though.

Thank you!

 

[XL83NL]

Apart from the sound engineering practice approach to determine if your product has sufficient strength, the PED 2014/68/EU may (indeed) require this calculation as well. Below is based on my assumption the PED applies to the UK; please verufy this, as Im not sure.

Here's what to do. Read the first articles of the PED, and go through the Annexes. I can tell you the quick n dirty answer, but working with the PED is something better learned yourselves than through the internet, as your OP also implied, you dont want ready-to-go solutions, which is a good start.

Your item may fall under PED table 5, provided it can be classified as follows

fired or otherwise heated pressure equipment with the risk of overheating intended for generation of steam or super- heated water at temperatures higher than 110 °C having a volume greater than 2 L, and all pressure cookers

Key here is if the heater is heated by energy transfer from one hot liquid to another (than its just a heat exchanger - tables 1 ÷ 4), or if energy is electrically or otherwise provided (you didnt specify).

Temperature is also key. Since you mentioned a working temperature, Im curious to hear the design temperature. You may end up in table 5 then, if the design is greater than 110 °C.

Design of the apparatus, regardless if it's subject to the scope of PED, can be done acc EN 13445 or EN 12952. EN 13445 is for unfired pressure vessels, 12952 for water tube boilers. Since you have an energy source with a potential for overheating (e.g. in case there's no supply of cold fresh water), 12952 may be more appropriate, but thats up to you to decide.

You may use ASME Sec VIII Div 1 but if your product is for the EU market, and falls under a category from the PED 2014/68/EU, EN 12952/13445 would be a more logical approach. Since they're harmonized standards, they have direct compliance with the PED and dont require further action to apply the CE-mark.

Hope this helps.