Installing black-water tank : questions ???

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krissteyn

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Had a quick search but could not find answers here - please comment freely...

I have an existing blackwater tank that was never used / connected and am having it fitted here in Cyprus. The locals dont need it , but I will need it elsewhere... (Turkey etc.)

I need to cut the hole for the "honey-boat" extracting mechanism/hose.

Questions........
1. what size is the hole and what fitting does it use ?
2. is it fitting on the deck , or on the side of the hull ?

I have searched , but in the fog of all the info , I have not found the detail...

Thanks Kris SV Footprints Latchi Cyprus
 
It could be useful to know that there is now an ISO standard for this fitting: EN ISO 8099:2000.
The BS standard in the Tektank link is possibly superseded by this.
 
BabaYaga said:
It could be useful to know that there is now an ISO standard for this fitting: EN ISO 8099:2000.
The BS standard in the Tektank link is possibly superseded by this.
Click to expand...

As a former member of the Standards Mafia, I'd just like to point out that ISO standards must be issued as a BS standard to be of effect in the UK. The standard ref you've given (EN ISO 8099:2000) is in fact a BS standard; the ISO standard is just ISO 8099:2000.

There is a reason!

Most standards issued by ISO are generic in scope. They don't include things that are required for local use, and may well include material that is irrelevant for local use. So, there are various ways an ISO standard can be brought into use in a country.

1) The standard is adopted "As is" by the national standards body. This is the most common course of action, and the standard mentioned above has gone that route; the EN (actually, BS EN) in front of the ISO designation indicates that it has been adopted by BSi. This can only happen if the BS EN standard is word-for-word the same as the ISO standard; any modification triggers the next possibility.

2) A BS standard is created which implements the ISO standard, but with adaptation for local circumstances. The UK standard for addresses (BS 7666) does that; it is an implementation of ISO 19112 (which is very general) taking account of the way that addresses are expressed within the UK. The degree of adaptation can vary enormously; BS 7666 is FAR longer than ISO 19112 (which is about 5 pages; BS 7666 is a book!) As nations differ enormously in the way that addresses are assigned and expressed, you can see that a detailed international standard is very difficult (though I think it is being worked on).

3) If an ISO standard is seen as being irrelevant to the UK, then it will not be adopted AND HAS NO FORCE IN THE UK. This can happen if the standardization covers matter that is culturally or legally unacceptable in the UK, or which is held to be covered by stronger local standards already. Lots of IT standards fall under this, as they cover things that for data protection or similar reasons are not legal in the UK, but are legal in other nations. Europe tends to be a lot more careful of personal privacy than the Far East, for example. I was at a meeting a few years ago when I caused a very quiet moment in a meeting by pointing out that something being taken for granted by an enthusiastic proponent of a new group of standards was in fact illegal in the UK (reverse lookup of phone numbers - and yes, I know you can do it, but it is illegal for all except the emergency services)
 
AntarcticPilot said:
If an ISO standard is seen as being irrelevant to the UK, then it will not be adopted AND HAS NO FORCE IN THE UK.
Click to expand...

I was only trying to help the OP by pointing out that there is an international ISO standard which is more recent than the one in tektank link.
From this link:

http://www.aquafax.co.uk/html/product_details.asp?ID=12496

it seems likely that the BS 7162 is similar to the older ISO 4567.

As he is located in Cyprus and indicates he might go to Turkey it is perhaps less relevant what rules are in force in the UK? (And I have no idea of the equipment used by pump out facilities in Turkey – the OP had better try to find out).

In practice I think the difference is small between the two standards when it comes to the deck fittings. The few pump out facilities I have used have had a rubber nozzle of conical shape suitable for various deck fittings.
If this is not the case there might be adaptors available (a bit messy, though).
 
BabaYaga said:
I was only trying to help the OP by pointing out that there is an international ISO standard which is more recent than the one in tektank link.
From this link:

http://www.aquafax.co.uk/html/product_details.asp?ID=12496

it seems likely that the BS 7162 is similar to the older ISO 4567.
Click to expand...


Actually, I was pointing out that the standard you reference IS a British Standard - the EN prefix means it has been adopted by BSi. ISO standards that are adopted by BSi are not given BS numbers - they simply become BS EN ISO whatever. I then went off into irrelevancies that may be of wider interest.
 
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Try to arrange for your pumpout to have a straight vertical run up from the tank and make sure the tank has a decent size air vent - 25mm is common.
 
Tranona said:
Try to arrange for your pumpout to have a straight vertical run up from the tank and make sure the tank has a decent size air vent - 25mm is common.
Click to expand...

If it's a gravity draining arrangement I have heard it suggested that it's a good idea to arrange for the outlet to be directly below the pumpout too, so it can be rodded through from the deck if it gets blocked.

Boo2
 
Boo2 said:
If it's a gravity draining arrangement I have heard it suggested that it's a good idea to arrange for the outlet to be directly below the pumpout too, so it can be rodded through from the deck if it gets blocked.

Boo2
Click to expand...

Yes, that is correct and how both the tanks I have installed are arranged - and it works. However, some have a dip pipe for extraction so that may not be possible.
 
Tranona said:
make sure the tank has a decent size air vent - 25mm is common.
Click to expand...

As I'm planning a refit soon, 2 questions on vents: What size and where?

My current holding tank had hijacked the water tank vent fitting on the boat's side. Water tank breather now terminates inside and makes a constant annoying popping sound which I'd like to rectify. It's either 13 or 19mm certainly not 25mm. I note tek tanks don't even sell 25mm vent fittings. Is 25mm really common/recommended?

I've always assumed that cutting a hole in the side of the boat was the correct way to fit a vent. Is there any school of thought advocating fitting on deck (presumably out of the way of toes)?
 
laika said:
As I'm planning a refit soon, 2 questions on vents: What size and where?

My current holding tank had hijacked the water tank vent fitting on the boat's side. Water tank breather now terminates inside and makes a constant annoying popping sound which I'd like to rectify. It's either 13 or 19mm certainly not 25mm. I note tek tanks don't even sell 25mm vent fittings. Is 25mm really common/recommended?

I've always assumed that cutting a hole in the side of the boat was the correct way to fit a vent. Is there any school of thought advocating fitting on deck (presumably out of the way of toes)?
Click to expand...

In my experience 19mm is fully sufficient. I upgraded from 13mm to 19mm when arranging for pump out a few years ago.
Also seems to be the general recommendation here (we will have a general ban on discharging to sea in 2015, lots of boatowners in this process now).

And yes, high up on the side (if you should ever over fill).
 
laika said:
As I'm planning a refit soon, 2 questions on vents: What size and where?

My current holding tank had hijacked the water tank vent fitting on the boat's side. Water tank breather now terminates inside and makes a constant annoying popping sound which I'd like to rectify. It's either 13 or 19mm certainly not 25mm. I note tek tanks don't even sell 25mm vent fittings. Is 25mm really common/recommended?

I've always assumed that cutting a hole in the side of the boat was the correct way to fit a vent. Is there any school of thought advocating fitting on deck (presumably out of the way of toes)?
Click to expand...

The vent on KS (fitted by LeeSan to the previous owner's order) is 38mm. The idea is to let enough air into the tank for aerobic bacteria to thrive, rather than anaerobic which smell worse. Small hoses, especially long ones with many bends, won't allow much air exchange.

You want the vent in the topsides, so that if it ever overflows it goes into the sea rather than all over the decks! :eek:

Pete
 
It has been suggested, originally by the Headmistress, I think, that having the vent as forward-facing as possible is beneficial. I'm not too sure about the physics of this if the intention is to get some sort of forced draught into the tank.
 
To the icy pilot , having worked extensively with British and American standards , I take your point , however , unless you translate it into Greek and Turkish , I am afraid its lost to the recipient of my "tank". What I have received here is in-valuable info - and for that I am eternally greatful - if you see Footprints , knock on the hull and expect your rewards :<)

The breather may be an issue - I have a carefully created 316 SS tank , installed and never connected 16 years ago. I am dragging it out and testing it , and then putting brand new hoses everywhere. As none of my previous boats had a blackwater tank - this is new to me - the best I had was a porta-potty....

My back will not survive the painfull twisting required to fit this and I have employed a local well recomended fellow to do it. He is an emigre from Bulgaria and has a good reputation.
So I am holding thumbs here.

We are using locally sourced non-jabsco macerators (2) to move the S*1T which I hope are OK. I wont be near the guarantee when it "ceases to function" - but we dont normally use the "tank" - altho that modus operandi will change soon eneough....

Cheers Kris
 
vyv_cox said:
It has been suggested, originally by the Headmistress, I think, that having the vent as forward-facing as possible is beneficial. I'm not too sure about the physics of this if the intention is to get some sort of forced draught into the tank.
Click to expand...

Not so sure about forward facing. When sailing heeled right down to the deck the water would be scooped into the tank! I have mine facing 45degrees backwards. At that point I should have reduced sail already!

However, a small always running bubbler might be a very sensible thing, like you have in a fish tank, but you would need to find one with a slow amp consumption.
 
Chris_Robb said:
Not so sure about forward facing. When sailing heeled right down to the deck the water would be scooped into the tank! I have mine facing 45degrees backwards. At that point I should have reduced sail already!
Click to expand...

Mine is in the side, around midships. I don't think any water ever gets in it, for that to happen something must come out to give it space. Without another vent it just isn't going to happen, hence my doubts about the Headmistress advice.

However, a small always running bubbler might be a very sensible thing, like you have in a fish tank, but you would need to find one with a slow amp consumption.
Click to expand...

In Shell terms, this is called 'sparging'. Oil storage tanks beneath the concrete production platforms are treated in this way to prevent H2S generation. Could be a useful thing to do but the practicalities probably make it not worth the bother.
 
Boo2 said:
Mightn't that be a possible source of flooding when heeled ?
Click to expand...

Not if you have an upward loop in the hose. Mine goes up inside the cockpit coaming, so that would have to be immersed (never come close to happening!) before any water came in. And then all it would do is fill the holding tank.

Pete
 
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