Drainage for process facility 3

[MHSpurs]

Hi Guys

Our firm have just been awarded a small extension to a process facility. Its our first job of this type where we have been asked to do the Civils/drainage.

The existing underground drains taking the process waste are clay pipes. Is this usual? The existing facility is only 10 years old. I would have expected uPVc, or concrete drains.

Can anyone shed any light on this? Also, does anyone know of a design guide specifically for drainage for pharma or process.

Your help would be much appreciated!!!

MH

 

[runoff]

MHSpurs;

That is strange for a 10 year old facility. Process waste is usually a form of PVC, HPDE or another form of polymer piping to handle different waste streams (i.e. pH, toxicity etc.) When I worked in the electronics industry, we had to use polymer piping all the way to wastewater system. From the wastewater system to our outfall and on to the municipal system was RCP. Usually the semiconductor, electronics and pharm industries follow a very similar standard for water and wastewater treatment.

I hopw this helps a little.

 

[GoldDredger]

In some parts of the country clay pipes are commonly (and successfully) used for sewer systems.

The Sacramento region in particular uses a great deal of clay pipe. There is a large clay pipe manufacturing plant (Gladding/McBean)north of the city that excavates clay from an old river bed onsite. Then they manufacture the pipe, I took a tour of the plant once, it was impressive.

Anyway, clay pipe does offer some benefits. For one, clay is inert against caustic waste and it offers very good scour resistance. It is also a rigid pipe with large wall thickness, so it has good compressive strength.

Conversely, clay is similar to concrete in it has poor tensile strength. So an uneven distribution of load could cause it to crack. It also has brittle qualities like ceramics, so it can be suseptable to impact forces. The contractors in Sacramento are familiar with its installation, so it seems to serve the region well.

Maybe the principle drawback is that clay pipe is heavy and comes in shorter segments (like 8' lengths, where PVC maybe 20') So that increase installation cost to some degree.

Anyway, I wouldn't say that clay pipe at this plant would necessarily be considered unusual or problematic.

 

[bimr]

Not familiar with anyone that is still using clay sewers for sanitary applications. Most sanitary sewer districts do not allow clay pipe any longer because of the potential I/I problem.

The clay service sewer may be left over from a previous facility that occupied the same site, where the service sewer was reused. I am familiar with one application where that occurred.

If all that you are doing is working on the service sewer, then you should contact the local sanitary district. The local SD usually has specific requirements. The service sewer is the lateral --the pipe between the 8"+ sewer in the street and the building.

 

[bpattengale]

The Cities of St. Paul and Minneapolis still use clay pipes for their main line sanitary sewer. Services are PVC but they like to see the mains be clay. If installed properly VCP can last in excess of 100-years.

As stated before clay is an inert material and will last a long time. It is bittle and succetable to impact damages.

PVC is easier to work with and more forgiving of improper installations.

 

[bimr]

Not so fast.

Vitreous clay pipe was the dominate player in the sanitary sewer market for over 100 years, but clay pipe has lost over 90% of the market share in the sewer pipe business to other pipe products. The clay pipe product has poor joints, short lengths that exasperate this design weakness, and it is heavier and more expensive than the plastic pipe alternative. Rather than improve the product design to meet the demands of the market, the clay pipe industry sat on their hands and lost the business.

The competitor’s superior joints, lower costs and ease of installation killed the clay pipe industry. Clay pipe is a good product but it is no longer competitive. The clay pipe industry did not accept the call to evolve and therefore clay pipe is no longer the dominant product in the sanitary sewer market. The predominant player in the sewer market is PVC pipe with over 75% of the market share.

There may be a few laggards still installing clay pipe in sanitary sewers, but with a North American market share of less than 2% and declining, clay sewer pipe is like the steam engines, a thing of the past.

 

[GoldDredger]

I don't doubt what bimr says above is true with respect to clay pipe loosing market share.

I wouldn't categorically say that clay pipe has poor joints though, which was a failing common with older pipes. And yes poor joints would a problem compounded with shorter segments.

I can't speak for other clay pipe manufacturers, but Gladding/McBean provides a very good joint and self locking gasket. Here is a link to a technical illustration.

http://gladdingmcbean.paccoast.com/...URL=/gladdingmcbean/docs/csp_PipeJointIll.pdf

Clay pipe also has historic data to support having a service life of 100+ years. Something PVC can't offer yet (though it looks like it will do just that)

Clay pipe is also rigid and as such doesn't deflect like PVC is prone to do. This deflection of pipe can have an adverse affect on the joint itself as well.

In my opinion their are pro's and con's to both types of pipe, but I don't see either being categorically superior to the other. Also, when we are talking about a regional industry with close ties to the community and economy, I'm not sure a completely opposite direction is warranted.

That being said, where I am now (Texas), I would never call for clay pipe on any of my plans. But, when in Sacramento, sure. Contractors are familiar with it, many juristictions there require it, and it keeps 300+ people employed at the factory.

ps. 'drainage' is usually a term used for storm water type flows, etc. 'effluent' would be a more appropriate way to describe process waste.

 

[MHSpurs]

Hi Guys

Thanks for all the help.

Can anyone recommend a good source for 'effluent' pipework design?

Hi Runoff, do you mean pvc or upvc? Has upvc got good chemical resistance? Also, why use two different materials?

Hi Bimr, what is I/I - not familiar with this term?

Thanks again to all!

 

[bimr]

In regards to "Can anyone recommend a good source for 'effluent' pipework design?", would you expand a but on what you are looking for?

I/I is excess water caused by infiltration and inflow into buried sewers.

 

[RWF7437]

"Can anyone shed any light on this? Also, does anyone know of a design guide specifically for drainage for pharma or process."

MHSpurs, What you have described sounds, to an old Civil Engineer like me, like a sanitary sewer or an industrial waste sewer. The terms "pharma", "process" and "effluent pipe work" are so vague as to have little or no meaning to us old guys.

My first question would be where does this system drain ? Does it go to public sewer system and treatment plant ?

If so, your design will be governed largely by that public system's standards.

If it goes to a private treatment or pretreatment plant then your design may be governed by the characteristics of the effluent being transported and treated. Does that effluent contain toxic, explosive, corrosive, biologically hazardous, radiological or similar materials? If so, can you quantify them and can your treatment remove them ?

For ordinary, i.e domestic, wastewater here are two possible references to go along with your local standards:

ASCE Manual of Practice No. 37 and
Wastewater Systems Engineering, Homer W. Parker,Prentice-Hall, 1975.

These will give you the "basics" but you may need much more if your effluent is markedly different than ordinary waste streams.

good luck

 

[MHSpurs]

Hi Guys

Thanks again for the replies.

I am quite familiar with general domestic and commercial sewer design (both foul water and surface water for residential, offices, shopping centres etc).

What I am looking for is a reference that is aimed specifically at industrial buildings. Something that will highlight the things to look out for for designing drainage for a process facility e.g rodding access points and maximum centres, pipe material for different chemicals/ph's, possible differences in trap types and when to use them, floor gulleys for gmp facilities, possible means of onsite treatment before discharging to public sewer etc.

My background is mainly structures (and their local drainage which up to now has been very basic) and to use a comparison: in structures the basics are applicable to every building but it is easy enough to get a reference book for the 'tips of the trade' when designing say office buildings, steel sheds, highrise, leisure etc. Is there anything like this for civils for Industrial and process buildings? Numerous searches have drawn a blank!!!

thanks again

MH

 

[bimr]

What you are looking for is an in-house piping standard.

Guidance supplementing piping standards is necessary because the various codes provide no explicit rules for functional design, material compatibility with fluid and environment (erosion/corrosion protection, radiation effects, etc.), layout, serviceability, steam tracing, grounding, valve and component selections, design of pipe supports, material traceability, gasket selection, as-built tolerances, insulation, cleaning for special process, etc.

For certain services some options available through piping codes must be excluded made more stringent or supplemented by the designer.

Larger CPI and HPI corporations have in-house piping standards that guide the design of piping systems.

If you do not have access to any corporate standards, I would build on the standards that were developed by other firms. It would be wise to read through a few of these standards for design inputs.

Have are a couple of references:

http://engstandards.lanl.gov/engrman/6mech/pdfs/D20-AppA-ASME_B31.3-r1a.pdf

US Army Engineering and Design - Liquid Process Piping

http://www.usace.army.mil/publications/eng-manuals/em1110-1-4008/toc.htm

 

[RWF7437]

Because this is an existing plant you have available to you two "references" which will be better than any book, program, standard or advice you can get in this forum.

First, you can view as many of these things as are available:
1. Plans and specifications for the existing plant.
2. Original design documents, including review comments, standards, calculations and similar data.

These can be used as models of what could or should be done so view them with skepticism. They may be available from the Owner, Reviewing agencies and, if you're lucky, the original designers.

Second, you may be able to obtain operational records from the Owner's employees. If possible, get effluent flow data, sampling, water use records, existing discharge permit and monitoring records, waste stream characteristics and problem reports. Even anecdotal data is of value. If such records don't exist, consider creating then yourself.

good luck