48-years of learning and I feel like keeping up with changes in PHVAC is less of a marathon and more like a mad dash. The old days of carrying just a flashlight, 4-way screwdriver, and a pair of water-pump pliers are but a pleasant memory of simpler times. PC boards did not exist. Electronic ignition was not yet a gleam in some engineer’s mind. My very first service call – sent out on my own on that first day – turned out to be a thermocouple. Looking back at the changes witnessed over the past five decades not so much as nostalgia, but more as history in the making.
Plumbing. In the early 70’s, cast iron with lead and oakum joints were standard. During sanitary sewer installations, you’d set up a lead pot that sat in a cradle over a 30-Lb propane tank/burner assembly. One of my jobs as the apprentice was recycling lead drain lines we removed during bathroom re-roughs by melting them down and pouring lead pigs. We still have several dozen lead pigs I poured in the early 70’s. The pigs would go into the pot to be melted and a ladle full of molten lead would be carefully handed down to the mechanic in the ditch. The older gents I worked with had been weaned off of lead with wipe joints just a few years prior. When I spied rubber gasket joints and a metal tool for pulling the cast iron bell and spigot joints together, it was obvious this would be a labor savings. My bosses Herb and Scott Behler were decidedly skeptical and to convince them I bet my week’s pay that Paul Strayer and I could do two sanitary sewer installations in the time it was taking us to do one with pouring lead joints. I kept my paycheck and we never looked back. Progress!
ABS plastic was next and the transition from cast iron to plastic required a calk-joint fitting that got packed with oakum and poured lead. We learned on that first poured lead-joint that you had to wait for the joint to cool before calking the lead or your tool would drive through the softened ABS. PVC arrived a few years later and became the preferred plastic for DWV applications. For many years, our local AHJ inspectors would not allow plastic to be used below grade. A few townships would cling to that notion for far too long! Initially, at least one of a home’s vents was required to be 4”. Clear primer gave way to purple so the inspectors could tell at a glance if primer had been used to etch the PVC surface glaze to properly solvent-weld the joints. Candle and peppermint tests gave way to air and water testing of installed DWV systems.
Push tapes and hand-spun augers were the forerunner of motorized sewer and drain line cleaners. Acids were used more frequently and we once ruined a Christmas turkey in the three story apartment building when the fish scales in the third floor drain line cut lose only to form a new blockage just past the branch line serving the first floor kitchen sink – where the tenant was thawing the turkey. The acidic slurry backed up to cover the lower half of the bird and the tenant was madder than a wet hen! Today you’re as likely to deploy a jetter as a motorized drain-cleaning machine. Camera inspection systems have become the norm for many plumbing firms and locator devices that can pinpoint the camera’s location and depth. Color constant-level videos can be recorded on a thumb-drive or sent via WiFi right to your customers’ computer, laptop, or smart phone.
How many ways can you heat potable water today? In the 70’s we were either looking at a chimney-vented tank-style oil or gas water heater or an electric model or a tankless coil in a boiler. Standing pilot for gas models with a thermocouple. For you youngsters who may never see a thermocouple, the tip that at least 1/3rd was to be in the pilot flame concealed two dissimilar metals that were welded together. The heat caused the two metals to expand, creating stress, which created millivolts of electricity the gas valve would “see” that allowed the burner to operate. When the weld joint cracked, no more millivolt power was generated and the gas valve would shut off on safety. The pilot didn’t always go through the gas valve and older models had B-valves (handle shaped like a B) that would continue to feed raw gas even if the pilot flame was extinguished! Today we have tankless gas models some manufacturers state have 98% efficiency!
We never had to give thermal expansion any thought because buildings did not have backflow preventers to block water from returning to the municipal mains. When water companies first installed dual-check backflow devices we began encountering bow-legged hot/cold tank inlet/outlet piping because the tanks had deformed from the rise in water pressure from thermal expansion! We quickly learned that a properly-sized thermal expansion tank was required for all water heaters on municipal systems where backflow preventers were present. Some creative things arose: ballcocks that would “weep” if system pressure rose to high; cheap thermal expansion tanks that were only rated for 125-PSI; misleading information regarding thermal acceptance capacity, which led to my experimenting with several size tanks, their acceptance, and ruining several air compressors (but a definitive article in CONTRACTOR that eliminated all the mumbo-jumbo and delivered the straight facts); and some screwball ideas like adding a bypass line from the hot outlet to the boiler drain said to eliminate thermal expansion relief valve dripping: hello – water is not compressible! Easily disproven by attaching a pressure gauge and getting the water heater turned on while no water was being used in the system.
Awareness of thermal scalding issues has grown significantly. Now there are ASSE-certified pressure balance, thermostatic, or combi valves built into tub-shower faucets or as add-on devices for under-sink applications, or to protect older tub/shower faucets by adding the device inside the wall, close by in the basement, or at the tank-style water heater’s outlet, and for tankless coils. Where tank-style water heaters once were set for 140F from the factory and residential dishwashers had no sanitizer rinse to being set for 120F, which caused dishwasher manufacturers to incorporate a sanitizer rinse cycle with on-board heating element to raise the water temperature back to 140F or higher.
And nowadays there’s so much more education regarding Legionella bacteria amplification issues in our potable water systems and what can and should be done to protect the health of our customers. I’m proud of the fact that my editors at CONTRACTOR magazine allowed me the leeway to lead the charge on what was, at the time, a highly controversial issue and raise awareness of the dangers certain practices present regarding bacterial amplification.
One more change: this is my final column for CONTRACTOR magazine. No one is quite sure how long I’ve been writing the plumbing column – myself included! Steve Spaulding, my editor, said he has been here for almost 23-years and that he’s pretty sure I was writing the plumbing column when he started. It has been both an honor and a pleasure to write to you each and every month over the past decades. Thank you for taking the time to be a reader and a special thanks to all who took the extra time to comment and provide feedback. Happy Trails!
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