By Main Line, PA refinance we mean refinancing your Main Line, PA home mortgage i.e. paying off your current Main Line, PA mortgage by getting it financed using another Main Line, PA home mortgage loan. In simple terms, that means using one home loan to pay for another home loan (for refinancing, we have both the home loans being taken for the same house). Generally, you go for mortgage refinance in order to take advantage of lower home mortgage interest rates (i.e. lower than what they were when you took the home loan). 
When it comes to refinancing a home mortgage, the first thing you need to check is the viability of this option. And the best way to do this is to get some mortgage offers. With internet, getting mortgage quotes or refinancing quotes is really easy. You can just go to of the various websites that offer to provide mortgage and refinancing loan offers in quick time.
Once you have these various refinancing offers, you can see for yourself if it would be viable to go for Main Line, PA refinance. Also take note of the various costs involved with refinancing (these include closing cost, valuation costs, fees etc). 
Generally, mortgage refinance is suggested when the prevailing mortgage interest rates are much lower than the interest rates on your current mortgage (lower by about 1.75-2 percentage points). Another reason for going for mortgage refinance is the need for cash (as in emergency), which can be generated by parting with your home equity. However, in any case you will need to check the viability before you proceed with your Main Line, PA refinance.