Recent content by SL1000

Hi what sort of accuracy is usually asked for / achieveable for the various custody transfer technologies mentioned here? Regards

so good stuff above but I've not absorbed it all yet.. 1/ So what does tying the signal common (or return) to the screen actually acheive. And how does this help? 2/ Also am I right in assuming that in the talk of circulating currents (in the screen or cable armouring and earth) is due to...

Thanks John Sometimes you can get wind of what standards are applicable at pre-contract meetings but I have found that by the time orders are placed standards just come out of the woodwork which can cause extra heart ache. I know you should not do too much until you have a clear picture but...

Hi Can anybody suggest the best way to find out which standards apply to which country/operation?? Is there an efficient approach to this? Does a database exist? Thanks

Yes good point sorry about that I saw related stuff in the other electrical / electronic group too. Not sure how to put a link in from here..

Excellent discussion. skogsgurra you make a good point about ground pollution and screens which brings me on to my next point. I have seen varios screen connection systems for an IS installation all with their own system certificates. But wondered if anyone could explain the reasoning and...

Thanks.. So as somebody else has said the term clean earth and instrument earth are interchangeable? If so are these the points generally used for barrier earths and screen termination?

Thanks for that info guy so do I take it if clean and instrument earth are interchangeable that IS circuits could use them for the point of termination of the screen or barrier earth?

Can anyone explain the difference between the above? In the main the diffrence between and requirement for both a clean earth and an instrument earth. Thx

Can anyone explain the difference between the above? In the main the diffrence between the clean earth and instrument earth. Thx

Art mentions the USA government’s mandate in OSHA 1910 with respect to the upkeep of documentaion, in this case the P&ID. Is there an equivalent requirement in the UK/Europe besides good engineering practices and if so what is it? Thanks SL1000

Radar is a possibility, but may be touch and go with the quoted dielectric constant. This is on the threshold of many radar antenna systems. However if a fixing can be made on the base of the vessel then a guided radar can be used.

Thanks for the replies, from what you have both added I take it then that the actuator although possibly physically suitable for the job it cannot be used in the UK without ATEX certification on a hazardous (zone 2) application. Also that even the butterfly valve that it modulates needs to be...

Thanks jmw certainly food for thought there. Your mention of mounting on a tank may be useful as the feed lines to the centrifuge don't need much of an escuse to sand out, a bit of runaway rubber lining would cause a nice blockage when introduced to a fork. I think the feed is fairly...

Please can you oblige with guidance on a hazardous installtion I have come across. I will be consulting with various experts and manufacturers but just need a heads up so I can iron out what I need to know. I've recently stopped a job until I can clear this up. A ball valve on a methane gas...