When you are in the guts end of the plumbing business, you will have to deal with things like water mains and sewer force mains. That means you will need the right equipment to do your job the right way. You will need pumps that fit with what you do. With that in mind, you will need a seller that can provide what you need.
You will need a hydrostatic test pump to really get it all going, pun intended. Sometimes you will have to use that pump to force chlorinated water through a main when you are repairing it in order to make sure that the main can clearly pump clean water safely through the main. If you do not have a test pump then you could not do this.
Not only do you need a test pump for this but you need to be sure it can handle the chlorinated water up to ten percent chlorine. Think about your needs for a pump before you order. With the right pump on your side, you can do any job and complete it with flying colors. You will be in charge of what comes in and what comes out, literally.
You know that when you get on a job and you are expected to get the water going, you had better do the job right so you can indeed get that water going where it needs to go. You cannot have it going just in any direction. You will have to make sure that you have it going in the right direction at the right concentration and so on.
As long as you have the right pumps, you should be fine. Go online and find out about the test pumps that you will need. Trust a company that has been in the business for a good number of years.