Search results for query: *

Artisi, thanks for the detailed response. Yes, I would presume the OEM seals would have been designed for the service, and we are using replacement OEM seals, but apparently there has been some material changes made already to address corrosion found in earlier failures. And I agree that with...

Thanks for all the responses. I'll try to address all the follow up questions, but let me give more background on my situation. I've been asked to assist another group who owns the system these pumps are installed in based on my more extensive pump background than the system owners...

And a second one...https://files.engineering.com/getfile.aspx?folder=95f36822-52a6-4f14-84c8-e8d5d6f462f9&file=Herborner_pump_2.jpg

I've attempted to upload a couple figures unsuccessfully to my original post...hopefully it will work in this comment.https://files.engineering.com/getfile.aspx?folder=37ac49db-7f5d-4af7-81dc-2b991a80acd9&file=Herborner_pump_1.jpg

We have had a high failure rate of sewage pump seals in a fairly new installation, which then leaks black water into the motor bearing with predictable results. The pump model is UNIVERS-A by Herborner. There are a number of system issues I believe are contributing to the failure rate, but...

Ed, thank you for the response. Let me ask for a clarification...where you say "The process is usually to abrasive blast the parts and then give them a quick pickle.", is that intended to apply to the option "...to have them acid cleaned after HT". I.e., is the quick pickle the same as the...

We procure pumps for our customer with casings made of CA6NM, similar to 400-series stainless steel that develops a thin rust layer on as-cast surfaces. Our customer objects to the rusty look, but would also like to avoid the lifetime maintenance burden of painting the pumps. My understanding...

Moltenmetal...thanks for your comments. "Think about it: if you're OK with an additive, why not shut off the electricity and just add bleach instead of making it in situ by electrolysis?" I think direct injection of chlorine in either liquid or gas form would be problematic due to the quantity...

Don't get me started on the system piping design with unventable pockets! At least the other high points in piping can be dealt with by adding vents, but the high points within the plate-and-frame heat exchanger represent the challenge. As a mechanical guy with low aptitude in chemistry, I...

We have a system that generates chlorine from the salt in sea water as a biofouling control in a condenser. We have a problem with hydrogen gas by-product collecting in un-ventable high points in the system, such as inside a plate-and-frame heat exchanger. Is there a chemical that could be...

At such a high flow rate through this size orifice, is cavitation likely occurring at the orifice, which I presume would throw off the DP to flow correlation?

Thanks for all the feedback. A little more background...I'm just the guy cognizant of the pump in the system while others have designed the temporary piping system and instrumentation to verify the pump flowrate prior to complete system construction and certification, and still others are...

I have a question about an orifice flowmeter installation being used to verify a pump is putting out its design flow and head. It has a 2.68" orifice in a 4" pipe, with 58" of straight pipe upstream and 15.75" straight pipe downstream. The question deals with the first downstream fitting: a...

Help me out here on where you guys are going with measuring the seal temperature. We do have a water temperature measurement, and I would think for all practical purposes, all the wetted seal parts are essentially at the water temperature (except for the seal faces themselves), and the external...

To add slightly to what GaTechTheron said, wherever we have pumps in parallel, we specify that the pump curves must be "continually rising to shutoff" for just the reasons he explained.

It is a Crane type 3710, size 3.625", part number NSP-1000044-1. The pump specification stipulated that the seal must operate over a temperature range of 32-120°F. What temperature range did you find for this seal, and where? I'd be shocked to find out the pump manufacturer selected a seal...

NegativeZero: The pump has been run on and off for several weeks, but the chiller just came on a couple weeks ago, and that's when the leakage started. We don't think the seal is shot, otherwise it wouldn't run leak free each morning before the chiller is turned on. They are about to rebuild...

1gibson: Yes, the seal drain port is at the 6 o'clock position, so any leakage past the seal is immediately drained away. And during initial pump testing, it was run for many hours without the chiller on with no leakage. It wasn't until the chiller started making cold water that the seal began...

We specify an allowed leakage of up to 30 drops per minute to account for that. But in our experience with these seals on several different design pumps, they are generally visibly leak free but sometimes on an initial start on a new seal, there is some small leakage that goes away as the seal...

The leaking seal is a Crane type 3710 split mechanical seal. It is designed for a temperature range of 32°-122°F. Is there any explanation for how the seal leakage could be caused by the temperature variations within the seal itself? That's why I suspect a pump/piping interaction, but the...