Acceptable Metal for Heat Exchanger for Liquid Silicate Solution

I'm in a quandry. I'm putting together a package for a customer and I need to find a heat exchanger. The application is for liquid silicate. Temperatures will range from 165 - 195 on the process side. I'll be using steam to heat @150 psig. The SpGr is 1.19, the specific heat assume 1. The ph = 10 -12. It is non-corrosive to mild steel. I thinking of using stainless steel tubes with steel body (steam in the shell) I'm just not sure if SS is a good choice. If possible, I'd like to use typically available materials.

Comments?