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NORA Oilheat Technicians Manual

and unevenly. You’ll probably also have water hammer. New steam boilers must be skimmed All steam boilers must be cleaned after they’re installed to remove substances that can cause foaming and surging of boiler water. It often pays to let the system run for a few days before you clean it to let the cutting oil and dirt have a chance to settle on the surface of the water. Skimming the boiler is the best way to remove cutting oil, grease, sludge, etc., from the system; it includes: • Inserting a 1 ¼" or larger nipple into a horizontal tapping above the waterline • Raising the waterline to the midline of the nipple • Draining water until it runs clear and clean Before you skim or clean any boiler, check the manufacturer’s instructions for their recommendations. One-pipe steam system One-pipe steam takes its name from the single pipe that connects each radiator to the steam main. Both steam and condensate travel in this pipe, but in opposite directions. This is what often makes one-pipe steam so difficult to manage. When steam and condensate travel in opposite directions, you have to pay close attention to the size and pitch of the pipes; the pitch must be at least one inch for every twenty feet. See Figure 13-20 for the layout of a one-pipe steam system. If you don’t follow these rules, you wind up with radiators that bang and air vents that spit. When replacing a steam boiler be sure you maintain the pitch of all the piping. Relief valve The relief valve protects the boiler against a runaway fire. On steam boilers the relief valve is set to open at 15 PSI. Gauge glass The gauge glass shows where the water is in the boiler. Expect to see some minor movement in the water line. Anything between a half and three-quarters of an inch of up-and-down movement is normal. Automatic water feeders An automatic water feeder is sometimes installed to maintain a safe minimum water level. While it’s not essential to the system’s operation, an automatic water feeder is a useful back-up safety device. Main vents Install main vents near the ends of every main so steam will travel very quickly to every radiator in the building. If your main vents are working, steam will arrive at each radiator at about the same time. Chapter 13 Heating Systems Chapter 13—Heating Systems 13-17 Part IV Domestic hot water Not only is Oilheat great for space heating, it is also the best way to heat domestic hot water for use in showers, baths, lavatories, clothes washing, and dishwashers. The production of reliable, inexpensive and efficient domestic hot water provides for the health and comfort of our customers and is one of our industry’s strong points.


NORA Oilheat Technicians Manual
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