STANDARD SPECIFICATIONS 1. Waste Gas Burner shall have a 6-inch size waste gas connection. Burning capacity shall not be less than 200,000 SCFH gas at 1/2-inch water column pressure drops. Burner shall be designed to burn waste gas composed of primarily methane, having approximately 550 to 600 BTU value. Waste gas shall pass through a "curtain of flame" developed by the ring-type pilot. Waste gas shall be deflected across the pilot flame by a baffle that is integral to the burner stack. Pilot observation and inspection port shall be provided on the burner stack. 2. Burner stack shall be equipped with a mounting plate for field installation of an electric pilot igniter constructed of 304 or 316 stainless steel and aluminum cover. The pedestal shall include a gasketed and separate base plate suitable for mounting on concrete or steel support. The burner stack shall be equipped with dual pilots, located 180° apart. 3. Burner pedestal and stack shall be fabricated of 316 stainless steels. Pilot flame ring shall be heatresistant 304 or 316 stainless steel. The pilot orifice and fittings shall be 304 or 316 stainless steels. Pilot gas connections shall be ½-inch NPT. Maximum waste gas inlet pressure shall be 20 inches water column. 4. A secondary stack shall be supplied if recommended by the manufacturer. 5. Waste Gas Burner shall be Varec Biogas 239A Series or equivalent. 2. Manual Pilot Ignition System A. A manual/cycling electric pilot ignitor shall be supplied for use with the waste gas burner. The control panel shall include a compact ignition transformer and an adjustable timing relay. The enclosure shall be fitted with an external three-position "Hand-Off-Auto" switch. The panel enclosure shall be NEMA 4X Stainless Steel. The transformer shall be energized when power is applied, and the switch is in the "Hand" position, it will deliver continuous high voltage to spark the ignition electrode. B. When the three-position selector switch is turned to the "Auto" position, the timer shall be activated, and it will alternately energize and de-energize the transformer that cycles the ignition spark. The timer provided shall have an independent adjustment for spark duration and spark interval. Both times shall be adjustable from 3 to 300 seconds. C. A separate ignition electrode assembly with weatherproof housing shall be supplied for installation on the burner stack. The ignition electrode housing shall be 304 or 316 stainless steels with aluminum cover. The control panel enclosure and electrode housing shall be provided with ½-inch NPT female conduit connections. Manual/ cycling electric pilot ignitor shall be Varec Biogas 240HOA Series or equivalent. 3. Back Pressure Regulator A. Single port regulators shall have 6-inch size flanged connections. Regulator shall be used for upstream control and shall be set to maintain 2 to 12 inches of water column back pressure, pending on the user. B. A large spring-loaded diaphragm shall control regulator valve. The regulator shall operate normally closed and shall maintain back pressure within approximately 10% of the setting. The spring barrel shall include a glass-enclosed pointer and scale to indicate setting. A spring adjusting screw shall permit setting adjustments without disassembling the diaphragm housing. Setting range shall be from 2 to 12 inches of water column pressure. C. Construction shall be low copper cast aluminum body, diaphragm and spring housings, and diaphragm inner plate. Inner valve shall include low copper aluminum pallet with 304 SS stems and bushings. Diaphragm shall be molded BUNA-N rubber with Nylon reinforcement. Setting spring shall be zinc plated steel. Valve shall include ½ inch NPT connections for the pressure sensing line and atmospheric vent line. Tubing provided by Contractor per the manufacturer's recommendations. D. The unit shall come with a three-way solenoid valve. The solenoid valve will open and close the regulator based on PILOT ON/OFF indication from the burner control panel. E. Backpressure Regulator shall be Varec Biogas 386 series or equivalent. 4. Insulating Jackets A. Outdoor installed units shall be provided with an easily removable 1-inch-thick insulation jacket. The insulation jacket shall be constructed with a silicone Impregnated woven glass cloth lining with a 1 inch thick, 6-lb density fiber glass insulating material. Through-cover quilting pins provide firm support for the insulation. The pins shall keep the insulation from shifting inside the liner and jacket for dimensional stability and uniform heat retention. The silicone lining has inside seams and folded closing seams with two parallel rows of stitching. The specially made insulating jacket shall be attached to the unit with a combination of Velcro and cinch belts. Insulation jackets shall allow access to maintenance on flame arrestors without removing the entire jacket.
