Ok, you're new here so some tips.
1) don't use CAPITALS - it means you're shouting.
2) Be a LOT more precise n your question, provide some back ground information, what you've ttried, size, type, pressure etc,
3) If you ask a really vague question then you'll get either no responses or vague responses
4) consider which forum to ask these questions in - this is the pump forum and surge vessels don't have any pumps... try a more suitable forum next time
5) Do a search on this site first - many similar questions have been asked before.
Until we know what type of surge vessel you have and why you haven't just read the manual or asked the vendor this question cannot be answered I'm afraid.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.