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formulas in the field

jonny88
jonny88 Member Posts: 1,139
Honestly how many guys use formulas in the field for offsets etc.Working in a building in the city which was demoed already.On original wall I could still see where math on the wall where original plumbers were working.
I will be honest and the few times I have used formulas especially on larger pipe it works a charm but old habits die hard and usually just use the eye unfortunatly.Wondering if there is any union guys here as I know they learn all this in school.Thanks.
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Comments

  • hot_rod
    hot_rod Member Posts: 15,066
    We had a union trained plumber working in our shop, he always had a pencil handy and calculated his offsets, even in DWV piping that was to be sheet rocked over.

    His workmanship was top notch, and many trades noticed and commented on his piping.

    Same with electricians that bend conduit.

    Probably an ap for that calculation now :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • jonny88
    jonny88 Member Posts: 1,139
    I actually saw an app what are we coming to, but it got bad reviews as it didnt take into consideration fitting allowances etc.Math was never my strong point but you cant argue with it as it works.Thanks
  • hot_rod
    hot_rod Member Posts: 15,066
    Math skills went away when the small hand held calculators arrived many years ago.

    When is the last time you have seen a cashier make change without looking at the display on the register. Not sure I would want that person doing math on the wall with a pencil :)

    But aps and computers are only as accurate as the data input.

    The engineering community struggles with this also. Are the software programs they trust calculated properly? Who, or how are they checked?

    Years ago the RPA ran heat load calc on a handful of radiant manufacturers load calc programs, numbers were all over the place even though they were all manual J based.

    So math is only as good as the person pushing the pencil, or stroking the keys.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • RobG
    RobG Member Posts: 1,850
    hot rod said:

    Math skills went away when the small hand held calculators arrived many years ago.

    When is the last time you have seen a cashier make change without looking at the display on the register. Not sure I would want that person doing math on the wall with a pencil :)

    But aps and computers are only as accurate as the data input.

    The engineering community struggles with this also. Are the software programs they trust calculated properly? Who, or how are they checked?

    Years ago the RPA ran heat load calc on a handful of radiant manufacturers load calc programs, numbers were all over the place even though they were all manual J based.

    So math is only as good as the person pushing the pencil, or stroking the keys.

    hot rod said:

    Math skills went away when the small hand held calculators arrived many years ago.

    When is the last time you have seen a cashier make change without looking at the display on the register. Not sure I would want that person doing math on the wall with a pencil :)

    But aps and computers are only as accurate as the data input.

    The engineering community struggles with this also. Are the software programs they trust calculated properly? Who, or how are they checked?

    Years ago the RPA ran heat load calc on a handful of radiant manufacturers load calc programs, numbers were all over the place even though they were all manual J based.

    So math is only as good as the person pushing the pencil, or stroking the keys.

    I completely agree, when you go to the grocery store and the total is one dollar and two cents and you hand the cashier a five dollar bill, they enter it into the register and it says you get three dollars and ninety eight cents back, then you check your pockets and find that you have two cents and give it to the clerk and they give you the deer in the headlights stare because the math has eluded them. It's very disheartening.
    SWEIMark Eatherton
  • rick in Alaska
    rick in Alaska Member Posts: 1,250
    I don't have to do it very often, but I do still do offsets with math. Usually just 45's on copper, but I do still do drainage work on occasion and will use it there also.
    Actually had to use it to set up my portable greenhouse the other day. I was laying out the base frame and was trying to get it square. Had to use the old A squared, B squared formula to get it done. I do need to get back to the books and do reviews though as I can't remember some of the odd formulas.
    I do however mostly use my calculator to run the numbers. My head is getting too old to do them mentally any more if they get too involved.
    Rick
  • RobG
    RobG Member Posts: 1,850
    I pretty much only use the 1.41 formula, if it's not a critical dimension I just use my tape measure.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,385
    I use 1.414 all the time on 45s. Most of the guys at work think I'm nuts so they use 90s because to them 45s are too much trouble (talkin piping not plumbing).

    I am not about to thread 2 1/2" and up or cut a pc of 8" to weld and have it come out wrong, too much work and too much waste.

    I like doing the math and then have it come out right.
    jonny88
  • jonny88
    jonny88 Member Posts: 1,139
    They think your nuts what a pity they wont learn.Do you find it takes more time to do your measurements using math or eyeballing it.....
    j a_2
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,385
    The way I look at it a little time with the math saves having to do it over plus in the larger sizes you can't hold it up there and get an accurate measurement, it has to be calculated
    RobG
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,385
    I know there is a way to calculate a rolling offset but I usually don't have the information when out on a job.

    What I do is to determine the locations of the two pipes by measuring. See the attached sketch. Then lay out the two pipes on the floor, wall or pc of cardboard, just like the drawing.

    Many time the pipes are some distance apart and you can't always use a "shooter" or a "gunner". I guess a laser would be nice. After you get the two pipes laid out simply measure the dotted line which is your cntr-cntr x 1.414 (if using 45s) and subtract for the fitting allowance.

    Works for me. How does everyone else do it?image
  • Gordy
    Gordy Member Posts: 9,514
    @hot rod said it best with computer programs in all facets of engineering. The new generation is putting all their trust in these programs. When one knows fluently the hand calculation steps to get the answer it is much easier to spot a glitch in a computer program calculation.

    The people that transitioned from long hand manual math to computer programs have this edge. As that generation cycles out of circulation the new generation tends to trust the computer programs more, and more. This leads to discovering things don't work out accordingly late in the game usually in the field where theoretical meets practical.

    I describe it as my wife gets in the car turns the key, and it starts. Really that's all she needs to know until the car does not start. She does not have a clue of what takes place in a series of events to make that happen. With out understanding all the things that happen once the key is turned its much harder to discover where the glitch in the system is, and fix it.

    Even the written word is slowly going the way of data stored on servers, hard disks spell check we as society are slowly becoming slaved to the digital era.

    That being said I just watched a video of a blind woman getting an ultrasound of her baby. The doctor created a 3 dimensional print of her ultra sound for her to hold, and feel what her baby looks like. Technology is indeed fascinating, and what we do with it.
    SWEIMark Eatherton
  • bob_46
    bob_46 Member Posts: 813
    layout the set on the blade of a square and the roll on the tongue measure across and times 1.41 .If you don't have a square use the corner of anything with a 90º angle. If you are doing a number of sets side by side and you want them all equally spaced each 45º has to start a little sooner. Multiply your center to center by .41 and that is your setback.
    bob
    EBEBRATT-Ed
  • RobG
    RobG Member Posts: 1,850
    Gordy said:

    @hot rod said it best with computer programs in all facets of engineering. The new generation is putting all their trust in these programs. When one knows fluently the hand calculation steps to get the answer it is much easier to spot a glitch in a computer program calculation.

    The people that transitioned from long hand manual math to computer programs have this edge. As that generation cycles out of circulation the new generation tends to trust the computer programs more, and more. This leads to discovering things don't work out accordingly late in the game usually in the field where theoretical meets practical.

    I describe it as my wife gets in the car turns the key, and it starts. Really that's all she needs to know until the car does not start. She does not have a clue of what takes place in a series of events to make that happen. With out understanding all the things that happen once the key is turned its much harder to discover where the glitch in the system is, and fix it.

    Even the written word is slowly going the way of data stored on servers, hard disks spell check we as society are slowly becoming slaved to the digital era.

    That being said I just watched a video of a blind woman getting an ultrasound of her baby. The doctor created a 3 dimensional print of her ultra sound for her to hold, and feel what her baby looks like. Technology is indeed fascinating, and what we do with it.

    Kids I have heard are not even required to learn cursive handwriting in school anymore, much less non-calculator math.
  • BobC
    BobC Member Posts: 5,232
    I still have a slide rule on my workbench.

    I remember a five ft one in the classroom were I was taught how to use one. If you know how to use a slide rule, math is no longer a mystery - it all makes sense.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    RobG
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,385
    @Bob, good trick with the square! I had a slide rule in school, guess they went out with the calculator. Wish I still had it, but would probably have to go back to school to learn how to use it....wait, there is probably no school teaching slide rule use.
    RobG
  • Gordy
    Gordy Member Posts: 9,514
    RobG said:

    Gordy said:

    @hot rod said it best with computer programs in all facets of engineering. The new generation is putting all their trust in these programs. When one knows fluently the hand calculation steps to get the answer it is much easier to spot a glitch in a computer program calculation.

    The people that transitioned from long hand manual math to computer programs have this edge. As that generation cycles out of circulation the new generation tends to trust the computer programs more, and more. This leads to discovering things don't work out accordingly late in the game usually in the field where theoretical meets practical.

    I describe it as my wife gets in the car turns the key, and it starts. Really that's all she needs to know until the car does not start. She does not have a clue of what takes place in a series of events to make that happen. With out understanding all the things that happen once the key is turned its much harder to discover where the glitch in the system is, and fix it.

    Even the written word is slowly going the way of data stored on servers, hard disks spell check we as society are slowly becoming slaved to the digital era.

    That being said I just watched a video of a blind woman getting an ultrasound of her baby. The doctor created a 3 dimensional print of her ultra sound for her to hold, and feel what her baby looks like. Technology is indeed fascinating, and what we do with it.


    Youu got it Rob. I love apple pie how do you make it. ;)

    Kids I have heard are not even required to learn cursive handwriting in school anymore, much less non-calculator math.
  • j a_2
    j a_2 Member Posts: 1,796
    Its not the kids fault, its the do gooders who tend to baby every kid that appears to have the smallest of learning issue..Mommy and my councler says I have the right to use a calculator for every test…Homework assignments are my option,because they really stress me out…If I sound cynicial I am….I taught on a half time basis,running my business the other 3/4 hrs left in the 20 hr days we all know about..It was a local city high school and I taught plumbing and heating to 11 th grade kids in a state of the art new tech wing attached to the high school.. Only for a few years because of budget cuts and lack of interest in students who thought plumbing work was hands on dirty work..The math and english and science teachers would tell the kids,that plumbing was a dirty trade….why would you want to be a plumber…..I chased a science teacher up a hallway calling him a moron for doing that...
    jonny88
  • j a_2
    j a_2 Member Posts: 1,796
    I like this
  • j a_2
    j a_2 Member Posts: 1,796
    With thisnull
  • BobC
    BobC Member Posts: 5,232
    @ja Its a shame they let the votech disintegrate the way they did. I took a 2 yr air conditioning night course at Quincy votech in the late 70's and was amazed at the poor condition the place was in. the instructors I had were all top notch as was the training I got there.

    I went to Don Bosco (run by the Salesians) in the early 60's (4 years of electronics) and that place was immaculate. If you did anything that required discipline, they handed you a bucket and some rags and told you to go wash all the windows on the 4th floor - inside and out. If they didn't like the way they came out you got to do them over until they did like the way they looked. If you gave one of the brothers any lip you got a backhand for your trouble and you knew their would be worse waiting for you when you got home.

    People were held liable for their actions and we turned out better for it.

    Everybody should learn a trade, even if they don't make it their life's work, you can always fall back on it when times get tough.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
    RobG
  • jonny88
    jonny88 Member Posts: 1,139
    @ja what the hell is null?......When you use the formulas and fitting allowances it really is not that difficult plus you save time on cutting pipe twice and wasting pipe.null
  • j a_2
    j a_2 Member Posts: 1,796
    I was trying to post a chart. For measuring angles. From u s navy pipefitters hand book
  • RobG
    RobG Member Posts: 1,850
    Some kids nowadays don't even know what an encyclopedia is. They have Wiki now. Not to be meant as an insult, but Asian kids are probably the only ones who know what a spelling bee is. Our American kids only know text message abbreviation. It's a sad state of society. Granted, I am in the country but I met a girl (friends daughter in high school) who could not tell me what day was new years or Halloween, her answers were, new years is the night that my parents stay out late and Halloween is the day I get candy. She is sixteen years old. :'(
    Gordy
  • Gordy
    Gordy Member Posts: 9,514
    RobG said:

    Some kids nowadays don't even know what an encyclopedia is. They have Wiki now. Not to be meant as an insult, but Asian kids are probably the only ones who know what a spelling bee is. Our American kids only know text message abbreviation. It's a sad state of society. Granted, I am in the country but I met a girl (friends daughter in high school) who could not tell me what day was new years or Halloween, her answers were, new years is the night that my parents stay out late and Halloween is the day I get candy. She is sixteen years old. :'(


    How about reading a map, telling time with a clock that has hands, multiplication tables, Yes high school.
  • RobG
    RobG Member Posts: 1,850
    edited May 2015
    Gordy said:

    RobG said:

    Some kids nowadays don't even know what an encyclopedia is. They have Wiki now. Not to be meant as an insult, but Asian kids are probably the only ones who know what a spelling bee is. Our American kids only know text message abbreviation. It's a sad state of society. Granted, I am in the country but I met a girl (friends daughter in high school) who could not tell me what day was new years or Halloween, her answers were, new years is the night that my parents stay out late and Halloween is the day I get candy. She is sixteen years old. :'(


    How about reading a map, telling time with a clock that has hands, multiplication tables, Yes high school.
    Future leaders of America. I think that in the mid eighties high school trade courses in my state were deemed not worthy of the financial expense as all parents assumed that their kids would be doctors and lawyers. Now those kids are living in their parents basements and working at Applebee's.
  • Gordy
    Gordy Member Posts: 9,514
    If you have not seen it watch this.
    jonny88
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,195
    Pipefitters handbook in truck or back pocket for decades now. I make my kids read it when they are working with me.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
    RobGZman
  • j a_2
    j a_2 Member Posts: 1,796
    Johnny. Null comes up with a quote.... Did u get the charts
  • jonny88
    jonny88 Member Posts: 1,139
    got the charts.i got a similar book at home and use the 45 offset on bigger jobs,but with pex its all out the window.Thanks for the link
  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
    edited May 2015
    UA Pocket Reference Chart
    shows all typical offsets 22 & 1/2 , 45, 60, 11 & 1/4 & 5th bends.
    It also shows decimal equivalents of a foot as well as equal spread take off for multiple pipes on rack making offsets and how to keep spacing even.
    I would guess I use it at least a few times a year too
    It's been in my wallet since 1983!
    For some reason I can't post a picture from phone to HH..
    I don't know what I'm doing wrong........ aaarrrggh
    Charlie from wmassjonny88
  • Shane_2
    Shane_2 Member Posts: 144
    Gordy,

    Thanks, I wish someone would listen to Mike Rowe in our schools.

    Don't even get me started on the kids today, I'll be that grumpy old man I used to make fun of when I was little. But come on, your on the clock kid put the phone down!
  • Gordy
    Gordy Member Posts: 9,514
    We are drifting off topic, but the sad part is the trades can offer someone a very comfortable living.

    , Most trades can offer a better living than a lot of proffesions requiring a degree, and 100 grand to get it. If they have ambition.

    Sadly ambition is lacking in this day, and age. I see more, and more a sense of entitlement. Use to be as an apprentice you busted your **** to impress your foreman, and elders in the trades wanting to know what they know, and more so someday you can be that guy. Seems today they want to get by, and collect a pay check doing no more than they have to.
    jonny88RobG
  • Paul48
    Paul48 Member Posts: 4,470
    I've watched my 3 grandkids as they have gone through school. They literally spent 2 months on estimating mathematics....what a load of BS. They never spent any time learning , what we called multiplication tables, or the relationship of it and division. Mathematics is the purest of all the sciences...and the only thing we're teaching our kids is 2 plus 2 is around 3.
    Hat....If you want to talk about the race to the bottom....Look at the educational system in the U.S.
  • Gordy
    Gordy Member Posts: 9,514
    edited May 2015
    No kid gets left behind.......whether or not they are ready to move on, they move them on. No sense of humiliation to give ambition if there is no threat of being held back a grade.
  • Paul48
    Paul48 Member Posts: 4,470
    They are systematically pushing good teachers out. Those that can, are retiring early. If you have a personal relationship with a teacher, ask them about what's going on. It's frightening. My grand-daughter is a junior in a private high school. Her best friend is a junior in public high school. Her friend is working on things she worked on , in her freshman year. If that's not being left behind, I don't know what is.
    RobG
  • jonny88
    jonny88 Member Posts: 1,139
    My Wife has a doctorate and ended up teaching.She echoes everything you are saying.
  • BobC
    BobC Member Posts: 5,232
    You need to test so you can see if the material is being retained. In the 50's and 60's we were tested and compared to others in our grade nationwide. We were told how to take the test but I never thought we were being taught just to pass the test.

    I know my HS diploma is a lot better than any current 4 year college degree (and at least equal to a masters) because of the wide range of subjects we covered. I went to a vocational HS and took electronics so I took seven years of math in those four years so I could handle the formulas you need to calculate values in circuit design. We knew there would be a test every Friday in each subject to make sure we adsorbed that weeks material because if you didn't get last weeks material you would never get the next weeks material.

    In the late 60's Nixon gave the Japanese cart blanch access to our domestic electronics market in exchange for their tacit approval; of the war in Vietnam. That was the start of the decline in our ability to produce domestic electronics. Now we don't have the ability to do much because there has been no need for the last two generations. Instead we send our kids to college where they learn how to shuffle papers or run the local burger joint.

    The race is over, we are at the bottom. Tell your kids to learn Chinese, they will need it to obey the new masters.

    It's just as well I'm on the way out, I don't take orders well - just ask my old company commander.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,195
    Not all of us are so "optimistic" I think there is potential for great things and I with foster this in my children as I can not do much for other peoples children. My children are expected to get honors in school, anything less means they are not doing their work. If they are not getting high honors it means they are not doing their best. My little liberal utopia is actually doing pretty well with educating our youth even compared to the rest of the world, not just compared to the rest of our nation. It may also be because I am only in my early 40's.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
  • j a_2
    j a_2 Member Posts: 1,796
    null
    Like I was saying I was a 1/2 plumbing teacher in a local high school....until the budget cuts came in....I was resigning anyway... The system was a joke.....I attended parent teacher nights....my classroom was very lonely