I have various equipment on-site in terms of pumps and blowers that are fitted with DGS technology. Is it acceptable to perfrom a "bump" test on my motor with the machine coupled up if my equipment is fitted with dry gas seals? I have the ability to feed pressure to the seal assemblies during...
Control method is with a needle valve. I've never liked the flow orifice as you are unable to vary the flow rate should you require a higher amount of flow to reduce emissions at the secondary sealing cavity. I guess you could adjust pressure higher to induce more flow, but some secondary...
We have a pipeline application that is utilizing a primary wetted seal design (hydropadded) with a dry-running spiral grooved secondary (non-contacting design). What is a typical set pressure for the Plan 72 N2 source? I would think I have to have a minimum of 5-10 psig above normal flare...
I am using conventional tandem seals on a hig pressure ethane pipeline application. The pump is a multistage between bearing and the only flush take-off I have available is off the discharge end. I have about 800 psig and I am not wanting to take full pressure drop across a single orifice.
I am...
I was hoping one of the seal experts could advise how they typically approach changing the face profile of the primary ring when trying to increase/decrease the balance ratio for various reasons.
Is the adjustment typically made with the primary ring OD or the primary ring ID? I would think in...
I know there is a common problem with nitrogen accumulation, particularly in vertical stand-by pumps with gas seals using nitrogen as the barrier gas. Over time the nitrogen accumulation can lead to liquid displacement from the eye of the impeller and a rough start-up that often requires...
I have a question regarding the cooling water side of the API plan 21/23 system. What is the preferred industry approach to flow control? Do you recommend a simple orifice or a flow control valve? In addition, I would think a simple flow indicator on the outlet line would be suitable (Per API...
Thanks for the input by I think you misunderstood my question. I am wondering what types of flow control are typically used for the cooling water supply to the exchanger. I realize that through a plan 21, a flow orifice is typically used and of course a pumping ring for the plan 23 is used.
I...
Trying to get a feel as to how often you guys utilize an in-line flow meter on the cooling water supply upstream of the heat exchanger on a plan 21/23? I know the seal vendors typically require a certain cooling water flow to achieve "X" amount of temperature cooling and none of our exchangers...
JJ and flexibox,
Thanks for the response. That has always been my preferred approach to regulation and metering of the low pressure nitrogen purge and when my contact advised opposite it certainly surprised me.
My seal vendor has provided me a copy of a proposed control panel in support of a dry-running secondary seal to use nitrogen as the "buffer" gas.
I noticed on the drawing that the order of instrumentation on the supply leg is as follows:
Filter - Pressure Regulator - Pressure Gauge - Flow...
We have metal bellows installed on plant-wide flashinig hydrocarbon problems and are having issues with our plan 52 pots pressuring up during operation. I've been told "spring loaded" pusher seals are a better choice for flashing hydrocarbon services. Can someone please summarize the overall...
Can anyone please summarize the difference between a Union Unichem/Unilign/VCM pump models? Are they one in the same or are there differences? I believe all are ANSI styled pumps.
I've been told that the Isomag Magnum-S is suitable for completely flooded bearing housings, while the Magnum-C is not a good choice for this environment. Is this due to the "S" model actually being hydraulically loaded from the OD?
flexibox,
Thanks for the response. You would agree however, that the pressure off the plan 53A should never be relieved when adding "makeup" barrier fluid? This would place your seal in a "reverse pressure" situation and o-ring shift could possible manifest itself hanging-up when the correct...
I've never seen an answer to the question regarding why one face must rotate and why the other is stationary. I've always believed the best explaination as to why one face rotates is to generate a hydrodynamic seal by both viscous shearing and heat generation to "flash" off visible leakage...
If the pump is a verticasl turbine style model, than a plan 13 is really all you need. A plan 11 in that situation would provide zero flow as the respective pressures (discharge and seal chamber) would be equal.
I would think one scenario where you would want to have higher flow rate from the plan 11 portion is when dealing with a vertical multi-stage pump that has an upper-shaft line bushing that requires lubrication?
BTW, Thanks for the response.
I'm looking for the correct procedure to size orifice plates on both lines of an API Plan 14. My plant has a significant amount of vertical in-line pumps that are currently fitted with single seals using plan 13 flushes. We've calculated seal chamber pressures to be barely above suction pressure...
