I am purchasing a foreclosed home in Illinois with an approx value of 175k I am purchasing it for 50k cash I am borrowing the 50k from someone because seller would only do cash deal so I couldn't get a mortgage to purchase. Will I be able to get a Home Equity Loan right away to pay back the 50k loan.

You should be able to get either a home equity loan or a first mortgage. If the property appraises for anywhere near the $175K and you own it without visible encumbrances (the money you borrow would not be visible), then most leanders would be willing to grant you a home equity loan or line of credit for at least half the appraised value.

Is there any way of finding out approx value with out getting appraisal?

You can ask a local realtor. You can try and get comps, recent sales of comparable houses.

Are you buying this from current owner before foreclosure or are you buying it from the lender after foreclosure.

I am concerned that the seller wants a cash sale as he may try to pocket the amount and leave you with a lien encumbered house. You need to make sure that you get free and clear title.