UL 296-2017 pdf download

UL 296-2017 pdf download.Oil Burners.
16 Constant-Level Devices
16.1 A constant-level valve included in the burner assembly shall be mounted and secured in place independently of the fuel piping and shall incorporate an antiflooding device.
16.2 A burner that requires the fuel oil to be supplied to it by gravity, and which is intended for instaflation with a constant-level device to be provided and installed in the oil supply line at the storage tank or with an automatic pump to maintain a uniform flow of fuel. may be furnished less such pump or device.
17 Floats
17.1 A float in a fuel-oil control or safety device shall conform to the requirements of 17.2 — 17.4,
172 The submerged part of a float In a float-actuated mechanism shall provide a buoyancy equivalent to
150 percent of that required to operate the mechanism with which it is related.
17.3 A float in fuel oil is to resist damage because 01 contact with the fuel and any impurities that may be contained therein, such as sulphur compounds and water. A metal, ii used, is to have corrosion resistance equivalent to brass
17.4 A float arranged to reduce the risk of the discharge of oil at the burner shall be used only when an acceptable auxiliary means is provided to guard against float or float valve failure, such as an automatic shutoff device.
18 Fittings, and Piping and Tubing
18.1 An opening threaded for pipe connection shall be threaded In accordance with the Standard for Pipe Threads, General Purpose (Inch). ANSI/ASME B1.20.1.
18.2 An openwg for field attachment 10 pIpe larger than nomInal 3 Inch ANSI/ASME B1.20.1 pipe size shall be provided with a flanged pipe connection conforming to the Standard for Cast Iron Pipe Flanges and Flanged Fittings, ANSI/ASME B16.1.
18.3 A fitting, other than one conforming with the appropriate Arneitcan National Standard, having openings threaded for pipe connections, shall be capable of withstanding. without damage or leakage. the turning effort (torque), see Table 18.1, exerted as II to screw the fitting onto a pipe or Into a pipe fitting.
Exception: Fittings that comply with the Standard for Tube Fittings for Flammable and Combustible Fluids, Refrigeration Service, and Marine Use, UL 109 having appropnate ratings for the intended use are excluded from the requirements of 18.3.
19.12 A pressure-relief valve shall be connected into a fuel line In which pressure may build up in excess of that intended by the design. because of the closing of any valve in the assembly of the burner or when the oil is heated by a preheater.
19.13 Automatic safety shutoff valves shall be constructed and tested in accordance with the Standard for Electrically Operated Valves. UL 429 or equivalent nationally recognized automatic valve safety standard.
19.14 Manually operated valves shall be constructed and tested in accordance with the Standard for Valves for Flammable Fluids. UL 842. or equivalent nationally recognized manual valve safety standard.
20 Stuffing Boxes
20.1 If packing is used to restrict leakage of fuel dl around a shaft or stem, a stuffing box conforming to
20.2 —20.11 shall be used if the construction is such that it is necessary to adjust or renew the packing
to prevent leakage during usage or as wear occurs.
20.2 A stuffing box shall be provided with a removable, shouldered, unthreaded follower gland and with
a nut, spring takeup. or equivalent means for adjusting the gland to maintain pressure on the packing as
wear occurs.
20.3 A stuffing box for an automaticalty-operated stem shall be constructed to avoid binding of the stem.
20.4 If an adjustable stuffing box is used to seal an automatically-actuated stem of a safety device, it shall be such that any allowable adjustment of the packing take-up will not bind the stem sufficiently to prevent the device from functioning automatically. A gland shall be spring-loaded.
20.5 An automatic spnng take-up foq a gland shall employ a spring made of corrosion-resistant material or one coated to retard corrosion.
20.6 The physical characteristics of a take-up spring shall be such that it will advance the gland through not less than one-half its possible travel from its initial setting with the spring compressed.
20.7 At the advanced position of the gland, a take-up spring shall not require adjustment of the nut to prevent leakage from the stuffing box when tested under pressure of one and one-half times maximum rated pressure.
20.8 A stuffing-box gland shall be made of corrosion-resistant material. The assembly of paris shall be such as to result in compressing the packing against the stem when the stuffing box nut or yoke is tightened.
20.9 Before shipment, a stuffing box shall be fully packed with pliable packing material, the impregnation of which is not adversely affected by contact with fuel oil,
20.10 The structure shall be such as to permit repacking the stuffing box without requiring the assembly to be dismantled, and threads of a stem shall not enter the stuffing box recess.