Advertisement

Pump Pressure

Discussions about HPLC, CE, TLC, SFC, and other "liquid phase" separation techniques.

5 posts Page 1 of 1
Hallo,

I bought a used 1100 Agilent and have been trying since the past few weeks to get it to behave !

I have a Binary Pump which has a Purge Valve which is mounted on a fitting on the A Side Pump.

I have installed a brand new Purge Valve with the frit and gold seal (every thing brand new). Now as soon as I close the purge valve, the solvent starts to drip out of the treads of the purge value.

I have to admit that I have not turned the Purge valve beyond a certain limit to get it to fit very tightly, as I am scared of ruining the treads of a brand new purge valve. Nevertheless, I have tried to observe the pressure in the pump while the purge valve is closed (and it leaks).

It seems that the pump pressure does not go beyond 1 bar pressure. I assume that the system would need a minimum of 100 - 150 bar to be able to even flush solvent through a separation column.

My question:
Should I risk the Purge valve and rotate it further ?
I have not been able to locate a Wrench which fits properly in the small space between the purge valve and the purge valve seat. Is there a special tool for this.

Is there some thing else that I can do ?
Pressure test does not help, since the valve leaks !

I am obliged if some one could share their experience on this topic.

Regards

SG
I have to admit that I have not turned the Purge valve beyond a certain limit to get it to fit very tightly, as I am scared of ruining the threads of a brand new purge valve. Nevertheless, I have tried to observe the pressure in the pump while the purge valve is closed (and it leaks).
The sealing is made by the gold seal which is soft. The stainless steel used in the purge valve and the pump housing is pretty strong, doubt you can damage that.

I have not been able to locate a Wrench which fits properly in the small space between the purge valve and the purge valve seat. Is there a special tool for this. Is there some thing else that I can do ?
I think this is the first problem, why the above question was needed. You need a thin 14mm open end wrench for this, about $17.20, Agilent #8710-1924 (see http://www.chem.agilent.com/store/Store ... =8710-1924).

If you're in a real hurry, get a 14mm open end wrench and a bench grinder and eye protection and grind the wrench to about 3mm thickness. Agilent provided this wrench in the tools provided with new instruments. A similar 12mm version is needed to R&R the active inlet valve.
The pump filter blockage is the main reason for pump leakage and this makes the pressure doesnot go beyond 1 bar , so try to remove the pump filter , immerse the filter in 50% methanol and sonicate for about 15 min .

ph/Amr Tarek
Instrumental Unit Head at Otsuka Pharmaceutical Company
If you have only hand tightened the purge valve assembly into the pump then it will definitely leak. As Consumer Products Guy said, you need that thin wrench to tighten the valve onto the pump head properly. Actually you put just about all the torque you can manage with such a short wrench to seat the gold seal securely, just don't use anything other than your hand and the wrench.

I would send you one of our spare wrenches but I imagine the shipping would cost more than sourcing it from Agilent locally in Germany.
The past is there to guide us into the future, not to dwell in.
Many Thanks for your kind responses and generous offer.

Based on the responses, I think the trick may really lie in the wrench. I will post a video in the next days once I have tested it out.

Cheers.
SG
5 posts Page 1 of 1

Who is online

In total there are 2 users online :: 1 registered, 0 hidden and 1 guest (based on users active over the past 5 minutes)
Most users ever online was 4374 on Fri Oct 03, 2025 12:41 am

Users browsing this forum: Ahrefs [Bot] and 1 guest

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food & Beverage, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry