INSTALLATION, OPERATION AND MAINTENANCE MANUAL
Easco Boiler Corp 1175 Leggett Ave Bronx, NY 1047 T: 718.378.3000 F: 718.378.4560 [email protected] easco.com
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4.5.6 Combustion air systems shall be in accordance with applicable requirements
of most current accepted edition of NFPA 54 National Fuel Gas Code and pursuant to
requirements as provided for within fuel burning equipment manufacturers operation
and maintenance manual.
4.5.7 For hot-water boiler application, a water re-circulation loop is recommended
to accommodate reduced system return water temperature fluctuation providing for
tempered return water flow through the boiler. The Hot Water Supply Re-circulation Blend
Pump to return connection should deliver at a minimum rate of 1/2 GPM/BHP and is
controlled by a Minimum Water Temperature Aquastat. The Blend Pump should operate
at any time, to assure minimum water temperature, regardless of system load demand.
4.6 Operating Controls and Safety Devices
4.6.1 STANDARD STEAM TRIM – McDonnell & Miller No.157S Float-Type Primary Low
Water Cut-Off (LWCO)/Pump Control with Alarm Contacts & Gauge Glass Set & hand
operated gage try cocks and No.63-M Float-Type Secondary LWCO with Manual Reset;
Honeywell L404F Operating Pressure Control, L4079B High Limit Pressure Control
with Manual Reset, L4006A or L4006B Low Fire Hold Aquastat and L91B Modulating
Pressure Control; National-Standard Pressure Gauge of 4-1/2-in dial & 0-30 PSIG & ASME
accuracy; ASME Safety Valve(s).
4.6.2 STANDARD WATER TRIM – McDonnell & Miller No.63-M (MAWP 50 PSIG), or
No.150S (MAWP 150 PSIG), Float-Type LWCO with Manual Reset or PS-850-M Probe-
Type LWCO with Manual Reset; Honeywell L4006A Operating Limit Temperature
Control Aquastat, L4006E High Limit Temperature Control Aquastat with Manual
Reset, L4006A Low Fire Hold Aquastat, L4006A Minimum Water Temperature Control
Aquastat recommended and L991A Modulating Temperature Control; Industrial
Thermometer of 7-in scale & adjustable angle and National-Standard Pressure Gauge
of 4-1/2-inch dial & 0-60 PSIG & ASME accuracy or Combination Pressure/Temperature
Gauge of 3-1/2-in dial & 0-75 PSIG & ASME accuracy; Bell & Gossett 250°F Seal In-Line
Blend Pump recommended; ASME Safety Relief Valve(s).
4.6.3 ACCESSORIES AND OPTIONAL EQUIPMENT COMPONENT – EASCO Boiler
Corp. manufactures and offers a variety of optional and accessory equipments to
meet with system requirements. For additional information, contact EASCO Local Area
Representative, or EASCO Boiler Corp., 1175 Leggett Avenue, Bronx, NY 10474, Telephone
(718) 378-3000, Fax (718) 378-4560, E-mail
or visit us at
easco.com
.
Accessories and optional equipment are available at extra cost, including but not limited to:
•
Annunciators
•
Alternate or Optional steam or water pressure or water temperature controls or LWCO
•
Built-in domestic hot water tankless heater coils – for low pressure boilers only
•
Motorized or pneumatic feed valves
•
Bottom blowdown valves and drain valves
•
Feed stop and check valves
•
Furnace and/or sequence draft controls
