Pulleys and V-Belts

[Artrose]

Totally agree with what EHSX said in post #6, and.........

Simply stated, a pulley is a machine. A sheave is a component in a pulley. Grammatically correct, or not, the words pulley and sheave continue to be used interchangeably.

The real difference here is that a professional calls it a sheave, and the others think it's a pulley. Professionals, as they mature in our trade, learn a new language. Learning, and properly using that new language is extremely important when you need to accurately convey information.

It's telling when someone calls it a pulley. It's also telling if someone is not familiar with the industry standard for tensioning a drive belt. That is a piece of knowledge that newbies are taught very early on in their career.

[heatingman]

I personally could care less. I prefer the use of the word pulley.

Sheave always makes me think of a makeshift instrument for stabbing used in prison.

Also I was always taught like Beerme. Sheave was always an adjustable motor pulley. Everything fixed was just a pulley.

Nobody worth a damn is gonna be thrown for a loop if someone calls it a sheave or a pulley.


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[thatguy]

Rule of thumb... The least amount of tension without slipping is the best for most small systems. You get a quiet and long life that way.

I’m sure someone has already posted how to measure it properly already but many units it doesn’t really apply because that would cause noise and added friction (only noticed on some small fractional motors)

There is a bit of a real world art to it a lot of the time.

What size motors are you servicing?

[Artrose]

I personally could care less. I prefer the use of the word pulley.

Sheave always makes me think of a makeshift instrument for stabbing used in prison.

Also I was always taught like Beerme. Sheave was always an adjustable motor pulley. Everything fixed was just a pulley.

Nobody worth a damn is gonna be thrown for a loop if someone calls it a sheave or a pulley.


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I thought this place was supposed to be a place to share knowledge?

If you were to browse the Browing catalog you will find those variable pitch sheaves that you're referring to, listed as VP, or MVP.

For example, if I wanted to order a 3.5 inch variable pitch sheave for my small exhaust fan, I might ask for a 1VP35. If it was a two grove sheave, I might ask for a 2VP35.

It would also be important to know the number, and type of belts that I might need. Having the ability to calculate the belt length for my new sheave combination is also important.
Oh, and we don't willy nilly change sheaves.

We need the ability to calculate the rpms of our sheave combinations, the ability to calculate the new anticipated amp draw, and, if this is a fan, or water pump, you should have the ability to understand the fan curves, or pump curves associated with the equipment

[WAYNE3298]

It's surprising my comments caused so much controversy. It reminds me of when I corrected a guy that pronounced potable water as pot able water. When I told him it was pote able he refused to believe it until Webster told him so. The reason I corrected him was that he was about to call a client.

The dictionary is part of the reason sheave and pulley are commonly thought of as the same. One description that I know of is "a sheave is a pulley with grooves". That describes the difference but in terms that insinuate they are the same.

[JayMan7]

I thought this place was supposed to be a place to share knowledge?

Heatingman shares knowledge all the time. What’s your point? All he’s saying is that he personally doesn’t care which word is used because it’s not a big deal.

[JayMan7]

It's surprising my comments caused so much controversy. It reminds me of when I corrected a guy that pronounced potable water as pot able water. When I told him it was pote able he refused to believe it until Webster told him so. The reason I corrected him was that he was about to call a client.

The dictionary is part of the reason sheave and pulley are commonly thought of as the same. One description that I know of is "a sheave is a pulley with grooves". That describes the difference but in terms that insinuate they are the same.

I appreciate the comment and I’m glad I got to look into something new...also I’m guilty of using “potable” wrong since I looked into that as well. So I appreciate that as well.

I think the poor guy just wanted to know about belt tension. Even though a pulley can be called a sheave and vice versa it’s not that important. What was important was belt tension. Calling something a sheave just wasn’t something he needed to be corrected on especially since he’s new to the trade. Your original comment (whether it was intended this way or not) kinda made it sound like he was a fool for using the word “pulley”. Myself and a few others are just making the point that he doesn’t need to feel that way or worry about it. The truth is that it isn’t a big deal for any professional to use the word “pulley” so he doesn’t need to feel unprofessional for doing so.

https://phoenix-mfg.com/Pulley-Versus-Sheave_b_21.html

[ammoniadog]

A few months ago a guy lost his marbles and went off on a bunch of us for using the word "Freon". I think he might have gotten banned over it. In my opinion, using the correct term is important, but it's not worth getting your panties all wadded up if someone else doesn't.

Just please don't use the word "hot" before the word "water heater". That one always gets to me for some reason, and I have to fight the urge to blurt out "It's a COLD water heater, dummy!".

[JayMan7]

But isn’t a boiler radiator a hot water heater hahaha

[WAYNE3298]

I'm not going to go off on any of you. Please understand I wrote specifications for 25 years and terminology is crucial when writing them. The old adage that interpretation of the specs is per the engineer only goes so far. If a spec stands on it's own the engineers interpretation doesn't mean anything because there is no interpretation. For example if you say the shaft shall be made of 304 stainless steel.

This isn't not a big deal to me at this point at all.

[ammoniadog]

But isn’t a boiler radiator a hot water heater hahaha

I had to think about this one, but I'm pretty sure a radiator is technically a water cooler. Maybe you could call it a "heater water cooler". Oh hell, I give up. Call it whatever the eff you want.

[BBeerme]

Regarding the term 'hot' water heater, depends on when you consider the water hot versus cold. For example, if I want my hot water at 150*F, and the 'hot' water heater is cycling within a 20*F range, and I consider cold water to be 60*F or less, then I have a hot water heater.

[BBeerme]

Here's another one I had a 'discussion' with an engineer about. And for what it is worth, he was the single best engineer I have ever worked with.

We were to install two small boilers. Design water temp maybe 185*F max. I asked him why he called them boilers. He answered, because they are over 150*F. I said at normal pressures, water does not boil at 150*F. He replied in a weird way, something like, since the water is hotter than what is considered safe, they are boilers.

We kinda just looked at each other, neither of us accepting the others reasoning.

[JayMan7]

I had to think about this one, but I'm pretty sure a radiator is technically a water cooler. Maybe you could call it a "heater water cooler". Oh hell, I give up. Call it whatever the eff you want.

Hahaha yeah this is a twisted thread hahaha. Anyway the pun I was attempting to make was that the radiator is a heater that uses hot water making it a hot water...heater

[JayMan7]

Regarding the term 'hot' water heater, depends on when you consider the water hot versus cold. For example, if I want my hot water at 150*F, and the 'hot' water heater is cycling within a 20*F range, and I consider cold water to be 60*F or less, then I have a hot water heater.

Holy shit you just blew my mind

[71CHOPS]

The one that gets me is TXV valve.

[71CHOPS]

It's surprising my comments caused so much controversy. It reminds me of when I corrected a guy that pronounced potable water as pot able water. When I told him it was pote able he refused to believe it until Webster told him so. The reason I corrected him was that he was about to call a client.

The dictionary is part of the reason sheave and pulley are commonly thought of as the same. One description that I know of is "a sheave is a pulley with grooves". That describes the difference but in terms that insinuate they are the same.

Discussions like this help raise the trade as a whole.

[WAYNE3298]

I try to help chops but sometimes underestimate the reactions. The post with the container that had the rising air bubble excited a lot here. That one understandably is impossible for a lot of people to wrap their head around and I'm not poking fun at anyone.

[JayMan7]

I try to help chops but sometimes underestimate the reactions. The post with the container that had the rising air bubble excited a lot here. That one understandably is impossible for a lot of people to wrap their head around and I'm not poking fun at anyone.

Now I’m curious! What post are you talking about???

[BBeerme]

Wayne has a lot of good stuff up his sleeve !!