No open ended svp's, in high rise buildings

[Plouasne]

Just wondering what other posters think about the idea of non vented soil stacks, the tallest building in Dubai is supposed to be like this, I believe that its an Australian "idea", stub stacks off the main stack with an AAV stuck on top of it and inside an enlarged section of pipe, a "bladder" to take up the forward compression of air

The idea is that there is no roof penetration, which could leak rain water into the building

Apart from the looks of the things, (I saw some photos of them fitted in Hong Kong) bloody ugly, I am wondering about the build up of drain smells, etc, because the drains are not ventilated in any way

Another snippet of information, I came across was the enterprising Indian drivers of the septic tank emptying tankers, got fed up with waiting to dump the load at the local sewerage works, so started to dump the loads down the local storm drains, which wasn't found out until the rains came then a few hundred thousand litres of raw sewerage got washed out and onto the beaches

 

[Puddle]

The sewage thing happened back in January,so hopefully sorted out now,it must have cost them millions to clear up as there was thousands of tons dumped,you could say the biggest dump anyone had seen


And they were still charging 5/7 star prices to stay out there

Not funny for the marine life and coral reefs though and e-coly flying about


Would add in the interests of racisam,it was not only indian drivers but philipino,yemini and other nationalities also

 

[Plouasne]

Its a shame that they spoiled it I was out there in '65, only 5 miles of black top road then, I was with the RE's doing a badger distillation plant, at a place called Mirfa, miles and miles of sand one side and the Persian gulf the other, and bugger all else apart from a Trucial Oman Scouts (army) tented camp

Thats where I learned to walk (well run like the clappers) on water, being chased by a bloody great shark does tend to make you move a bit faster than normal

 

[Puddle]

Respest Plouasne,you were one of the pioneers
My father worked in the oil construction bussiness,was in the middle east about same time,Das island,Emerates ,ended up starting his own construction firm in Bahrain, in early 70's,went out there for 4 years as a teenager,then came back,as you know,you have to have an arab bussiness partner and think my dad picked wrong one but he did ok, then did a few years in saudi in the early eighties working.
What transportation did you use to get out there in the sixties ?
Ps I was always corrected out there and told to name it the Arabian gulf...My first experiance of political correctness )

 

[Plouasne]

Bit of a long story really Puddle, but to cut it short, after doing an apprenticeship and a few year on the tools, plus being in the TA, I joined up was in the Royal Engineers
For the Trucial Oman Scouts, I was up country in Aden at the time, flown by the RAF to Bahrain first for a stopover then to Sharjah, then in the back of a 3 toner for 5 hours across the dessert
The aircraft were Avro Argosy twin tail boom, on the way back the flyboys forgot to collect the sandwiches so did a diversion to a camp where there was a bit of a "do" going on in the Oman and a lot of the boys there wore beige berets, if you get my drift, and to avoid any nasty incoming stuff, the pilots when airborne went straight up vertically, for the first 5000 feet, then gave us a sightseeing trip along the coast, pointing out the sharks in the water, and there were hundreds of them just off the coast

 

[david williams]

many soil stack instalation types ,from 2 pipe, single pipe,with anti syphon pipework,garche,vacum ,it goes on and on depending on country you live in pakistan has the most stringent sanitary laws on paper but some of worst in practice.think how lucky we are in gb

 

[Plouasne]

Ahhhhhhhhhhhhg,

The Garchy system, I did that on the Barbican, and a few other places

 

[david williams]

Ahhhhhhhhhhhhg,

The Garchy system, I did that on the Barbican, and a few other places

we should form the last of the plumbers who new the dinasours

 

[Plouasne]

Not all the old dogs are dead yet, what about 4" lead soil stacks

I remembered a tale from way back in '58, a Shoucksmiths (sp) apprentice plumber came into the tech one day saying "I'm working on a new type of gutter", what is it we all asked, "plastic" he replied, "cannot half earn a bomb on bonus" (because the bonus was still priced on cast iron guttering) no f***ing good 'cos it don't hold water"

Dave, just to give you a little bit of my work experience,nothing much out of the ordinary

12" Cast Iron drainage for the main rainwater drain, Jumbo jet servicing hangar Heathrow all hot poured lead joints, in the ground,
12" Cast Iron Tyton jointed fire main Enfield, (where Taylor Woodrow design engineer, forgot or didn't know about "Thrust Blocks" on the change of direction)
4" copper soil stacks luxury flats next door to Madam Tausauds (sp),
4" polythene chemical soil stacks, just across the road from the other job, spelter brazing loose flanges on 6" copper Old Bailey,
4" PVC solvent welding water mains,
4" Cast Iron caulked lead water mains,
6" cast Iron sewerage sludge main,
apart from the rainwater drain, copper, and polythene soil stacks , all the other cast iron was tested to 200psi for an hour,
I have also done 150mm Blue Poly water main, flat plate fusion but welding, and electro-welding the branches, 63mm yellow gas, but welding and hot iron saddle joint welding
I have also done a spell in a design office as a trainee draughtsman, but could not stick being cooped up all day long

And just for the hell of it raised 28mm and 40mm copper stop ends out of scrap copper tube, just to show the French that the English were better than they were, the French way of a stop end was either a dog rough purse hard solder end or a piece of copper hard soldered over the end of the tube and ground to shape

 

[NickH]

Yeah, but other than that what have you done !!

 

[Plouasne]

Yeah, but other than that what have you done !!

You don't really want to know do you ??, a not very civil, civil serpent, "mercenary" for HMG amongst other things

 

[HTB]

I've done ground runs on an Argosy if that helps, it jumbed the chocks when we put all 4 to max (which we shouldn't have done but it was fun). It was twin boomed with 4 Dart engines which had a vey high pitched whine thus earning it the nick name "the whistleing wheelbarrow".

 

[Plouasne]

Did you ever hear about the accident between a VC10 and a dumper??

Brize Norton, back in '66, 1 Troop 50 Field Squadron Royal Engineers were tasked with removing, parts of the bomb dumps at the airfield, and the route involved crossing the runway, temporary crossing lights had been set up on the one way only crossing, but this idiot decided that it was quicker to go in the reverse direction and was crossing the runway, just has a VC10 came in to land, the result was a tail dragging on the runway, when the pilot applied more power to abort the landing

 

[flat pack]

the good old daysssssssssssssss i remember them well

 

[TGor]

The Installation you saw in Dubai is an engineered system using a Positive Air Pressure Attenuator (PAPA) in conjunction with AAV's The PAPA was developed after extensive research into positive an negative transient pressures in SWV stacks at Heriot Watt University The practical application of this research is a good example of how traditional plumbing methods can be improved by proper scientific research.

rgds
TG

 

[Plouasne]

The Installation you saw in Dubai is an engineered system using a Positive Air Pressure Attenuator (PAPA) in conjunction with AAV's The PAPA was developed after extensive research into positive an negative transient pressures in SWV stacks at Heriot Watt University The practical application of this research is a good example of how traditional plumbing methods can be improved by proper scientific research.

rgds
TG

So how are the main drains ventilated then ??, that is the question

I am afraid that in my time I have seen too many, so called systems, fail after so called proper scientific research

 

[TGor]

So how are the main drains ventilated then ??, that is the question

By "The Main Drains" I assume that you mean the horizontal drains within the building in such cases they are not "ventilated" as such, the AAV allows air into the stack when there are negative pressures due to discharge and the PAPA absorbs the positive pressures to prevent trap seal loss. There is no attempt made to introduce fresh air ventililation into the main drains since providing FAI at the boundary trap is no longer done.

I am afraid that in my time I have seen too many, so called systems, fail after so called proper scientific research

For myself I would certainly be interested to hear from you regarding specific instances of such failures in your experience as very often such information does not get fed back to the people concerned.
rgds
TG

 

[Plouasne]

My reply is behind the copied quotes,

"By "The Main Drains" I assume that you mean the horizontal drains within the building in such cases they are not "ventilated" as such, the AAV allows air into the stack when there are negative pressures due to discharge and the PAPA absorbs the positive pressures to prevent trap seal loss. There is no attempt made to introduce fresh air ventilation into the main drains since providing FAI at the boundary trap is no longer done."

All drainage systems need to be ventilated to the open air, for a number of reasons
1) To relive the pressure on the soil stack, The Americans pre war were advocating an air relief pipe one size larger the the soil pipe, in high rise buildings
Refer to the Garchy system installed at the Barbican buildings City of London, where the original system of a 6" main stack with a 2" vent, and to be retrofitted with a 4" relief stack cross vented every other floor, I worked on the remedial stack
2) To enable the build up of dangerous gas's to be vented to the open air, Hydrogen Sulphide gas can and does attack concrete, Methane gas is highly flammable, another by-product of sewerage
3) I have personally observed, a range of two w/c's fitted as a range of toilets, with an AAAV, fitted at the correct hight, etc, this set of w/c's were on the first floor of a building, without any other appliance being fitted to the drainage system before the main drain, the total drop was about 10 to 12 feet, before it turned to become a drain in the ground which was about 50 feet run to the main drain, when the w/c's were flushed the water backed up in the pan, UNTIL THE AAAV WAS REMOVED ,the whole installation was as per the architects drawings (Cornwall County Council, in house architect, Saltash College of Education, was the job), the damp still air in the drain was of sufficient density to hold back the the water in the pans, when flushed, this was over come by fitting a 4" vent pipe through the roof to the open air, and doing away with the AAAV
There is no need for a FAI at the boundary of the building, because, now disconnecting interceptor traps, are no longer fitted to the individual drain from a property, before it meets the main drain/sewer, therefore the whole of the drainage system is ventilated

The "old boys" like Dent, Hellier, Stitson, White, et al, in the UK around the turn of the last century, (1910-1920) had it worked out, after the original plumbers, pre 1880 had made learning mistakes when mains drainage was first thought about

"For myself I would certainly be interested to hear from you regarding specific instances of such failures in your experience as very often such information does not get fed back to the people concerned."

Harbuts plasticine new factory, I only read about it, but briefly, it was a new building burnt down because of not researching enough, when specifying new materials to be used
Plasticine, needs to be heated for it to be pumped around the building, the old idea was steel tube with trace heating to keep the plasticine liquid for this, the new idea was to use PVC tube still trace heated, the problem came when the pipes were suspended off hangers, NOT A CONTINUOUS "LAY BOARD" as the PVC pipe should have been; Result, because the insulating properties of the PVC are more than steel the heating was increased, the PVC pipe softened and sagged between the hangers, finally breaking, the electric trace heating wire snapped, causing an arc, which ignited the liquid plasticine, end result a £2000000 building burnt down

South West Water, renewed/upgraded their Spine/Trunk water main, with 60cm PVC tube, within 15 years or thereabouts, they had ripped it out and replaced it with Cast Iron, reason, in summer SWW cut in diesel booster pumps, to increase the pressure flow rate in the trunk main, PVC cannot stand fluctuating pressure changes, it suffers from longitudinal stress fractures if the pressure is not constant

Parts of Germany are now no longer allowing PVC to be used because of toxic fumes when in a fire, they the Germans are now going back to the old egg shaped sewer, because of its better "dry weather" flow properties, but this time in plastic rather than in brick, as the material of choice

The new standard in France for septic tank drainage, is for two 100mm stacks both to rise to fresh air at high level, one is the normal SVP, the other is for ventilating both the septic tank and the drainage field, with a low level FAI at the end of the drainage field

 

[TGor]

All drainage systems need to be ventilated to the open air, for a number of reasons
1) To relive the pressure on the soil stack, The Americans pre war were advocating an air relief pipe one size larger the the soil pipe, in high rise buildings

The pressure changes in the stacks are dealt with by the devices as explained. The research carried out over many years at HWU (Edinburgh) proved that the open stack could not properly deal with positive & negative pressure transients in all circumstances leading to trap depletion.

Refer to the Garchy system installed at the Barbican buildings City of London, where the original system of a 6" main stack with a 2" vent, and to be retrofitted with a 4" relief stack cross vented every other floor, I worked on the remedial stack

I believe the Garchey system is a refuse disposal chute system?? However this goes to show that the original design to the regulations of the time was not up to the job and presumably this manifested itself with trap depletion?. Hopefully the larger dia vent solved the problem. Point being that regulations design manuals can never cover every circumstance. The development of devices to deal with these transient events inside SWV stacks make for a more stable system with the likelihood of trap depletion significantly reduced.

2) To enable the build up of dangerous gas's to be vented to the open air, Hydrogen Sulphide gas can and does attack concrete, Methane gas is highly flammable, another by-product of sewerage

See comment below…

3) I have personally observed, a range of two w/c's fitted as a range of toilets, with an AAAV, fitted at the correct hight, etc, this set of w/c's were on the first floor of a building, without any other appliance being fitted to the drainage system before the main drain, the total drop was about 10 to 12 feet, before it turned to become a drain in the ground which was about 50 feet run to the main drain, when the w/c's were flushed the water backed up in the pan, UNTIL THE AAAV WAS REMOVED ,the whole installation was as per the architects drawings (Cornwall County Council, in house architect, Saltash College of Education, was the job), the damp still air in the drain was of sufficient density to hold back the the water in the pans, when flushed, this was over come by fitting a 4" vent pipe through the roof to the open air, and doing away with the AAAV.

Interesting scenario it would be interesting to go a bit deeper into the physics of that one any chance of a sketch ??

There is no need for a FAI at the boundary of the building, because, now disconnecting interceptor traps, are no longer fitted to the individual drain from a property, before it meets the main drain/sewer, therefore the whole of the drainage system is ventilated.

This is an interesting point that you raise since some authorities appear happy to use building stacks to vent their sewers rather than making that provision independantly.

The "old boys" like Dent, Hellier, Stitson, White, et al, in the UK around the turn of the last century, (1910-1920) had it worked out, after the original plumbers, pre 1880 had made learning mistakes when mains drainage was first thought about

I bow to the “old boys”

Harbuts plasticine new factory, I only read about it, but briefly, it was a new building burnt down because of not researching enough, when specifying new materials to be used. Plasticine, needs to be heated for it to be pumped around the building, the old idea was steel tube with trace heating to keep the plasticine liquid for this, the new idea was to use PVC tube still trace heated, the problem came when the pipes were suspended off hangers, NOT A CONTINUOUS "LAY BOARD" as the PVC pipe should have been; Result, because the insulating properties of the PVC are more than steel the heating was increased, the PVC pipe softened and sagged between the hangers, finally breaking, the electric trace heating wire snapped, causing an arc, which ignited the liquid plasticine, end result a £2000000 building burnt down.

Nasty … But we could have told them that anyway!!!!

South West Water, renewed/upgraded their Spine/Trunk water main, with 60cm PVC tube, within 15 years or thereabouts, they had ripped it out and replaced it with Cast Iron, reason, in summer SWW cut in diesel booster pumps, to increase the pressure flow rate in the trunk main, PVC cannot stand fluctuating pressure changes, it suffers from longitudinal stress fractures if the pressure is not constant

Absolutely .. could have told ‘em that too!!!

Parts of Germany are now no longer allowing PVC to be used because of toxic fumes when in a fire, they the Germans are now going back to the old egg shaped sewer, because of its better "dry weather" flow properties, but this time in plastic rather than in brick, as the material of choice.

Now this is a good egg shaped idea especially with reduced volume flush

The new standard in France for septic tank drainage, is for two 100mm stacks both to rise to fresh air at high level, one is the normal SVP, the other is for ventilating both the septic tank and the drainage field, with a low level FAI at the end of the drainage field .

That’s another good idea because Septics can really get on the nose if not done properly

I remembered a tale from way back in '58, a Shoucksmiths (sp) apprentice plumber came into the tech one day (snip)

You don't by any chance mean Shouksmith's in York??? which might mean you went to Dringhouses Tech??

Rgds
TG

 

[Plouasne]

The pressure changes in the stacks are dealt with by the devices as explained. The research carried out over many years at HWU (Edinburgh) proved that the open stack could not properly deal with positive & negative pressure transients in all circumstances leading to trap depletion.

I believe the Garchey system is a refuse disposal chute system?? However this goes to show that the original design to the regulations of the time was not up to the job and presumably this manifested itself with trap depletion?. Hopefully the larger dia vent solved the problem. Point being that regulations design manuals can never cover every circumstance. The development of devices to deal with these transient events inside SWV stacks make for a more stable system with the likelihood of trap depletion significantly reduced.

See comment below…

Interesting scenario it would be interesting to go a bit deeper into the physics of that one any chance of a sketch ??

This is an interesting point that you raise since some authorities appear happy to use building stacks to vent their sewers rather than making that provision independantly.

I bow to the “old boys”

Nasty … But we could have told them that anyway!!!!

Absolutely .. could have told ‘em that too!!!

Now this is a good egg shaped idea especially with reduced volume flush

That’s another good idea because Septics can really get on the nose if not done properly



You don't by any chance mean Shouksmith's in York??? which might mean you went to Dringhouses Tech??

Rgds
TG

No Shoucksmiths of London, Harlesden I think the area was called, Willesden tech 1955 -1958 then again as an apprentice 1958 - 1963

 

[justlead1]

Hi. The purpose of ventilating soil systems, or so i am lead to believe is to allow the free flow of area through the entire sewage system. Disallowing positive and negative pressures and dispersing odour, gases and to help the self cleaning of drains, by drying/shrinking any deposits attached to the pipes above normaly flow level causing them to loosen and wash away at high flows. How is this achievable with such valves?

 

[Plouasne]

Hi. The purpose of ventilating soil systems, or so i am lead to believe is to allow the free flow of area through the entire sewage system. Disallowing positive and negative pressures and dispersing odour, gases and to help the self cleaning of drains, by drying/shrinking any deposits attached to the pipes above normaly flow level causing them to loosen and wash away at high flows. How is this achievable with such valves?

In my opinion, it is not achievable, there has been too much theory and not enough practical, coming out of so called further education/universities, most of it akin to snake oil salesmen

 

[TGor]

In my opinion, it is not achievable, there has been too much theory and not enough practical, coming out of so called further education/universities, most of it akin to snake oil salesmen

With due respect your comment is a generalisation not based on fact. There are many universities and technlogy institutes around the world doing great research into plumbing issues many of these are presented at the CIB W62 symposium held annually. Some of the outcomes are adopted by various plumbing regulators and others may be commercially developed.

The CSTB particularly M. Francois Derrien, is a strong contributor to these endeavours ... as you say are in France contact them if you are interested or google CIB W62.

However having said that I must agree that there are some individual issues that need more control .. I know of one "esteemed" professor of civil engineering at a university "up north" who "designed" a drainage system for a 3rd world country village in co-operation with a well known charitable organisation. I believe it was serving 2-300 people with a 3" drain and bodgy ic's needless to say they had to train several dyno-rodders who could hold the villagers to ransom.

This kind of thing must be more controlled and if charities are to provide water supply & drainage facilities (which of course they should) it is vital that the standards that we uphold ourselves should be applied and cheapskate "experiments" should not be allowed. Now these people are in a worse situation than before they were "helped"