Non-concussive taps, an "argument" with a colleague

[Stigster]

Hi guys. On the City and Guilds Level 3 course that I support as workshop technician, in the module on complex cold water controls they ask me to provide a "Concussive tap" and in the student worksheets also ask what is the main purpose of them.

The answer given is that it is a water saving device. That's all fine but surely they mean to say "Non-concussive tap" rather than just concussive? I am arguing with a colleague who insists there is such a thing as a concussive tap, that I need to find one and the documentation is correct and it's me that is wrong when I call them non-concussive and suggest the documentation contains a mistake.

I have tried to show him that if you search online for a concussive tap, you only get results for Non-concussive taps. Every supplier calls them non-concussive. To me, concussion is what causes water hammer and the self closing tap is non-concussive, preventing a bang when the tap shuts itself off.

It makes no sense to me that there would be a concussive tap, you want to prevent concussion, not install a tap that causes it!

Sorry for the long post I just find it very frustrating trying to convince people of what I think is a mistake but they are adamant that it is me who is wrong. I am as always happy to be corrected by those with the relevant knowledge. I will contact C&G for a definitive answer but I would also appreciate any input from you good folk.

 

[snowhead]

I'd say C&G have made an error.

I believe the term has become redundant as all push button self closing timed taps are Non-concussive nowadays.
The term no longer needs to be used.

The early ones wouldn't have been, they'd have just had a spring and no damper as now and when shutting off caused water hammer.
Non-concussive versions would have come about and manufacturers would be keen to point out that benefit, so the term appears to have taken over as a description of the type.

 

[Stigster]

Thank you for reading my novel length post and your input.

 

[quality]

It is C&G that is wrong. It gets my goat when people claim to have C&G this and C&G that. They are only an awarding body just like logic or bpec. They set no standards no regulations no industry rules but only issue certification like all of the other warding bodies do.

 

[Stigster]

As for the work that students produce, C&G do set standards. Work has to be done to +/- 2mm accuracy for instance. Work must obviously be sound. It must be completed in the (admittedly generous) time frame set for the task. The practical work also has a theory component that must be completed for the task to be signed off. When doing work in low carbon steel for example, accuracy standards must be maintained and the work piece "not excessively marked by tools". Standards are set and if they cannot be achieved they do not pass.

 

[quality]

Ive worked with, for and on behalf of C&G for over 20 years, as far as my experience goes as an awarding body they are not as good or up to date as many of the others

 

[Last Plumber]

The taps you are talking about have two types as @snowhead points out.

The earliest versions would close on a spring only and could have a concussive result to their action for obvious reasons.

The better version has a cylinder shaped water filled damper inside it as you know, to slow the closing of the valve and prevent the concussive effect. The latter are referred to as 'non-concussive'.

The non-concussive tap has been available for over 60 years that I know of. I cannot personally remember seeing a spring only version. All the taps I have seen in schools and public buildings over the past 30+ years have been 'non-concussive' types.

The spring only version did exist (maybe still does?) but as far as I am aware it was never referred to as a 'concussive tap'.

There have been 'self closing taps' and 'non-concussive self closing taps' for over 60 years.

Sometimes I do think that people run away with their own ideas and use language that Plumbers just wouldn't use.
Is he referring to 'normal' taps do you think?

 

[Stigster]

Ive worked with, for and on behalf of C&G for over 20 years, as far as my experience goes as an awarding body they are not as good or up to date as many of the others

That's a fair observation given your experience in the field. I responded because I disagreed with "They set no standards." However as far as not being up to date I can agree with that in many respects.

 

[Stigster]

The taps you are talking about have two types as @snowhead points out.

Sometimes I do think that people run away with their own ideas and use language that Plumbers just wouldn't use.
Is he referring to 'normal' taps do you think?

He's been a lecturer for the last 12 years but he has been a plumber for 50 years and he ran a very successful business for much of that time. He is a knowledgeable guy and I have a lot of respect for him. However he can be a real stickler for the details which in most circumstances is a good thing but this concussive tap business was bothering me so I came here.

I have since been able to convince him we aren't going to find a "concussive tap" using the info gleaned from you guys here so thank you. He had some vague recollection of learning the terms "concussive and non-concussive taps" in the distant past and that was causing a bit of confusion especially with the mistake in the source material I'm working from.

 

[quality]

That's a fair observation given your experience in the field. I responded because I disagreed with "They set no standards." However as far as not being up to date I can agree with that in many respects.

I can understand your point that they set standards but they are only driven or determined by industry standards and quite often old standards

 

[Stigster]

To all those who contributed here, thank you. I love this place. Now that I spend much of my week in the workshop with the apprentices and when I am on the tools it is almost always maintenance work, I really appreciate being able to read, answer, ask and learn on these forums. I feel in a general sense that it keeps me in the loop and keeps me questioning and learning.

Thanks for your time.