Hello Sirs,

I apologize if I ask obvious questions, I have a relative knowledge on the subject ... But let my questions ..
Currently my company uses Ridgid KJ-3100 sewer jetter machines (Vanguard Twin 16hp, gearbox and Annovi XWM2128 pump (4,000 psi, 5gpm ... although the Ridgid manual states that the pressure goes to 3,000psi, Ridig's manometer shows 3,000 psi, but it is possible to see the pointer over this mark)
The work of my company is mostly unclogs and drain lines in residences, small snack bars, and also condominiums (vilas). I do not deal with ultra-heavy cases, industries, with abrasive materials for example. I do not usually perform hydroblasting services (long time services), only unclogging, which usually requires 5 to 15 minutes of machine operation.
I intend to assemble 5 to 10 new machines for my teams, and now my questions..

1) Since my Ridgid machine complies with extreme ease 99% of the cases that I attend, I intend to reduce the specifications a bit. I intend to gain ease of movement when the employee will work alone, lower initial cost, and lower maintenance cost. I had thought of Vanguard 13hp (single cylinder) + gearbox + Annovi, General Pump or Comet Premium Pump 4,000 psi / 4gpm

2) I have doubts about the pumps, my Ridgid has an Annovi XWM2128 pump. Manufacturer Comet has premium RW, SW and TW lines. My question is whether Comet RW is equivalent to Annovi's XWM in terms of durability. (The weight of the RW is 20% less), and General Pump TS2021

3) I have already seen manometer connected straight into the body of the pump, and I have seen manometers connected after the output. What's the difference ?

4) I have doubts about the unloader, if I buy this 4,000 psi pump, and regulate the unloader to act at 3,800 psi. Is it a good security measure to increase system durability? Or if I buy the 4,000 psi premium pump I can always work at maximum without fear. (Remembering that 90% of my services are 5 to 10 minutes away)
Thank you immensely for your help,

Luis Rocha