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  1. mae1133

    ASTM A312 or A778 corrosivity

    So, overall, would you consider pipe manufactured to ASTM A312 to be superior to A778. I am tabulating some of the differences as follows, based on what I have found: • A312 is commonly used higher temp and higher pressure applications such as steam boilers, pressure vessels, etc. • A312 has...
  2. mae1133

    ASTM A312 or A778 corrosivity

    Generally speaking, does ASTM A312 or A778 provide better protection against corrosion. I have no specific application, but just trying to determine the main differences between the two standards for 304L/316L SS piping as related to corrosion.
  3. mae1133

    240V baseboard heater flash

    Yeah, I am definitely replacing it. In fact, I have the new one in the back of my car and will replace this evening, but just wondering if you guys have ever heard of anything like this happen. It is not on a GFCI, but it is not in a wet location either. I installed the one being replaced in...
  4. mae1133

    240V baseboard heater flash

    Hoping one of you electrical guys can offer a possible answer to this: I have a 9 yr old 1500W baseboard heater in one of my rooms. As I was walking by this morning, a loud pop and flash came from the middle of the heater (not at the junction box). Upon inspecting it, there was black residue...
  5. mae1133

    pneumatic vs electro-pneumatic valves

    Having a debate with colleagues whether there is a difference between these two types of pneumatic actuated valves. Can't find a clear definition which would explain the difference, but don't all pneumatic valves have electric solenoids (AC or DC) to control the air flow to the valves cylinder...
  6. mae1133

    sulfuric acid unloading and storage station

    I am working on a plant in NY that requires 93% sulfuric acid, so part of the plant is the design of the tanker truck unloading station to fill a 6000 gallon tank that will be located in an adjacent building. Can anyone point me in the right direction for codes and requirements for the...
  7. mae1133

    Preventing back siphoning

    Good point guys! The water rise is likely more due to oscillation during shut down as opposed to the vacuum created from the pipe cooling. I'm having them adjust the ramp down time on the blower to try to minimize this effect. They do have manual drains at the low point of the piping.
  8. mae1133

    Preventing back siphoning

    Attached is a diagram of the existing system. I'm recommending a siphon break at the high point of the piping at the top of the tank, but this is an inaccessible location, so the client has suggested locating it inside the building right after the blower discharge. I certainly prefer it being...
  9. mae1133

    Preventing back siphoning

    We have a client with an aeration system that consists of a 32' tall aeration tank with approx. 28' of liquid. The PD blowers are in a nearby building at ground level. The piping goes up and over the wall of the aeration tank to the bottom of the tank where the aeration diffusers are. When...
  10. mae1133

    Water requirements

    Thanks LittleInch, but I think you're mixing my flow and pressure numbers. The flow is 60 gpm and 50 gpm, so 110 gpm was what I was suggesting as a flow requirement but I would suggest a bit more as a safety factor. Likewise for the pressure, I would tell them a bit higher as an allowance for...
  11. mae1133

    Water requirements

    We have two pieces of equipment that requires process water in a new building. One requires 60 gpm @ 70 psi and the other requires 50 gpm @ 65 psi and will operate concurrently. We want to advise the owner of the total flow/pressure required coming into the building. Is this simply the...
  12. mae1133

    closed suction valve?

    Not to worry, I will notify here of our findings. It will also be documented.
  13. mae1133

    closed suction valve?

    I'm offsite, but have people in the field dealing with it. (Different side of the country) I'm just passing along things to look for or try.
  14. mae1133

    closed suction valve?

    These are 75 HP ANSI centrifugal pumps with 12’ flooded suction and 33.5’ total static head. (2500 gpm @ 79' TDH)
  15. mae1133

    closed suction valve?

    Static Readings: Suction: 4.5 psi on both pumps (This seems to be close to what the suction head of the tank is) Discharge: 4 psi on one pump gauge and 3 psi on the other So, when the pumps are turned on, the suction gauges go to 4 psi and the discharge gauges go to 2 psi.
  16. mae1133

    closed suction valve?

    We are still checking things, but they say the impellers are installed. I'm getting them to check the static PG readings as well.
  17. mae1133

    closed suction valve?

    Yeah, that's what I'm thinking as well. Other thoughts is actually a broken shaft, but that would be highly unusual, especially in both pumps. Wouldn't a blockage in the suction cause an increase in amps though?
  18. mae1133

    closed suction valve?

    Further information coming in: Rotation has been checked and the amps are 17amps FLA is 68. Suction is 4 psi discharge is 2psi.
  19. mae1133

    closed suction valve?

    We are starting up a system and apparently getting no flow from the pump and no increase in discharge pressure and low amps. I'm thinking the rotation may be reversed. I originally thought a blocked/closed suction, but upon checking the amps, I'm leaning towards a rotational issue?
  20. mae1133

    closed suction valve?

    What will happen to the discharge pressure gauge if you have a blockage or closed valve on the suction side of a centrifugal pump?

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