Cleaning New Equipment

[Mills]

I am just about ready to begin work on cleaning all of the vessels in my new brewery. The equipment is all new. What tips and tricks do you have for getting new equipment ready for beer, both internal and external?

Thanks!

[KWLSD]

My 'starter-for-ten'...

Have a good visual check that everything looks to be right; check that there aren't isn't remaining debris from cutting, welding , etc. (This should have been done by the supplier/installer but always worth assuring yourself!).

Our next step for new plant was to check for grease as machining compounds are often mineral-based. These show up with u/v light so a few cotton swabs wiped on surfaces and in any corners is all it takes.

If the plant is all assembled a run through with water will find any joints that need tightening and allow you to check that valves, etc. operate as they should.

Externally clean down with hot water, again look for signs of grease/oils which will shown up as areas where water forms beads rather than runs off cleanly.

Following that a good caustic clean, then rinse and you should be ready to brew!

[MatthewS]

Passivate?

I have always been told to passivate with Nitric Acid before the first brews on a new system. Of course yearly passivate is key to keeping your steel protected and in top shape.

Anyone care to add to passivating techniques that have worked for them?

For my last buildout, we did a full caustic of all internal surfaces, then a Phos/Nitric blend cycle, then a heavy duty straight Nitric Acid cycle for 60 minutes to passivate.

[biosonik]

Passivation really occurs in the next step. Where you allow to the steel to air dry and get exposure to oxygen after the acid rinse. Usually for a day.

[KWLSD]

Yep I'd assumed (so that'll be mistake #1, then..!) that the manufacturer would have passivated but certainly any additional welding will need doing at the very least.

[jfulton]

As stated previously, check that no foreign debris has wound up inside the vessels. I have found square inch pieces of scrouge pad in a couple. In one strange case, we had rinsed, cleaned with caustic, then passivated a tank to find a foreign piece of metal (soft iron I figure) at the bottom of the unitank, which during passivation, created a noticeable pit around it (electrolysis)! The whole bottom assembly had to be replaced because of this. There can also be many little pieces of metal that have found there way into the lauter tun and remain stuck between the wire. DO NOT ASSUME the manufacturer has removed every little bit of dirt/grim/metal shavings/etc. And some of this stuff can be introduced during site construction.

Anyways, after visual inspection rinse everything well and be sure no metal has accumulated at the bottom of vessels, especially below the lauter screens. Remove and clean all gaskets from manways and clean under their position. Replace the gaskets. Clean every vessel and all piping with an appropriate detergent at normal concentrations at 60-75 deg C for twenty to thirty minutes. Rinse well.

For passivation I add nitric acid to water (before heating the water) at a concentration of 2-3% (pay attention to the concentration of the nitric you're using) using around 200-300 liters of water. You can use many different acids (phosphoric/nitric blend, citric acid...), I just have always used nitric. Just ensure proper concentrations of different acids-don't have the literature in front of me. Heat the solution to 70-80 deg C. Say a prayer. Make sure you've got all you gear on (boots, glasses, parka, etc.), and start passivating the tanks. I run a 45 minute cycle through the CIP of each vessel, making sure it's at least 60 deg C. If you have multiple heated vessels (mash mixer, HLT, kettle), space them between the cellar tanks so you can heat the solution back to temperature during the passivation of those vessels. Be mindful to run the solution through all of your process piping also. If you have copper cladding, be careful not to let any dripping solution come into contact with it. Do not rinse after passivation. Remove all fittings so that the tanks are as open as possible, and drain any dead legs in your piping. Let everything sit undisturbed for around 24 hours.

[gitchegumee]

Please see the following post (and many others) on this subject. I recommend a getting the proper literature and doing some credible research on the subject. You've spent how much on new equipment and now you're going to throw hot concentrated nitric into it? I know I fell into the trap of listening to (and repeating) "Old brewers' tales" about drying after passivation. It's been repeated to the point of being accepted as true. There may be some document out there that DOES recommend drying without rinsing. But I'll put my faith in ASTM until then. Get the ASME documents and follow them precisely. Or hire someone who is insured and qualified to do the job. Good luck!

http://www.probrewer.com/vbulletin/s...1&postcount=10

[jfulton]

The process I've described is what is recommended by a very long standing member of the craft brewing community. I've never had a single issue with this procedure and never had "staining." The surfaces and welds are gorgeous afterwords and years later, repeating the same procedure yearly.

Phillip, what is the cause of the staining and the reason for rinsing? Sorry, I'm not a member of ASTM, cannot access the document. I'm very open to hear your reasoning. As I've stated in this post, this is just how I've always done it (and with good results).

Cheers,

[KWLSD]

There are two primary causes of staining:

1) Weld stain - this is where welding causes the build-up of iron oxide layers in the material immediately adjacent to the weld. Because these are iron-rich and, as such, chromium-depleted, they have a lesser resistance to corrosion;

2) Contaminant stain - the pickling process removes 'free' iron material from the surface structure of the parent metal where it has been welded. These would otherwise corrode. If pickling solution is not thoroughly rinsed away after the process, there is a danger that this will leave some iron-rich particles adhering to the surface of the structure and result in corrosion sites.

For both instances passivation increases the surface chromium content which then forms the protective oxide layer. It is therefore essential to have a scrupulously clean surface free to maximise this.

[Mills]

Great info, all! Keep it coming.

I was thinking about the exterior as well. Would it be ok to hit the exterior of the tank with a dye and fragrance free dish soap and hot water wash and rinse? I do have copper bands on all my tanks, is there products that should be used/avoided with those?

Thanks!

Mills

[KWLSD]

Hard soap can sometimes leave residues so might not be ideal. Hot water with a bit of detergent and a stiff brush, followed by a hot plain water rinse.

Avoid anything highly acidic/alkaline to keep your copper nice'n'shiny

[gitchegumee]

Jamie, I've been using the "air dry" method for 15 years before I actually read literature specific to passivation techniques. I too had "good results". But without a control whereby I would NOT passivate to acertain whether the "good results" could have been achieved without air drying, there isn't any conclusive results. I've had many, many craft brewing folks nod in agreement with the air dry method. Likely none were metallurgists. Surely none read the relevant standards associated with passivation. It's craft brewing urban legend as far as I can tell. Repeat something often enough and it becomes true. Is there ANY source of instruction for air drying besides "common knowledge"? Nobody ever questioned me on the several posts where I recommended air drying. Somebody should have. Just goes to show that a brewer must do his/her own due diligence in all aspects of brewing. As for staining, I have had staining when using pickling paste on new welds. Should have rinsed the area faster than I did. It gives a slightly frosted appearance to mirror polished surfaces. The ASTM document may be found at certain libraries. Ask an engineer or librarian friend to look it up. It is worth reading.

[Cache]

Thanks for the advice all - and Phillip. I will be passivating all of our new equipment soon, and have been researching the topic heavily.

This may be a bit repetitive, but this is what I've found: The best thing you can do is find ASTM 380-06 and ASTM A967. I went to my local university which has an engineering program, and was able to find both documents at the library. They subscribe to ASTM, so documents are free as long as you are at the library, on their wifi. Probably the same case at many schools around the country. I recommend that any brewer should seek out these documents for the good of their equipment.

Bobby Wilken
HooDoo Brewing Company
Fairbanks, Alaska