OSB 2 SERIES User Manual

OSB Series 2 Oil-Fired Steam Boilers – Boiler Manual
Part Number 550-110-772/0816 7
General
If installation is to comply with special codes, additional limit
controlsmayberequired.Ifinstallingaoat-typelowwatercutoff,
use only those devices that can be connected to the boiler gauge
glass tappings. Refer to the wiring diagrams on page 13 for correct
wiring location of additional limit controls.
Relief valve
Installboilerreliefvalveinthe¾”tappinginthebackoftheboiler,
usingthe¾”nippleandelbowsuppliedinthebagwithreliefvalve.
Follow the steps below to avoid potential severe
personal injury, death or substantial property damage.
• When installing the relief valve,ensure that all
connections, including the valve inlet, are clean and
free from any foreign matter.
• Mountthereliefvalveonlyintheverticalposition,
directly connected to the tapping designated in the
manual on top of the boiler.
• Usepipecompoundsparingly,ortape,onexternal
threads only.
• Donotuseapipewrench!Usepropertypeandsize
wrench on wrench pads only.
During operation, this valve may discharge large
amounts of steam and/or hot water. Therefore, to
reduce the potential for bodily injury and property
damage,adischargelineMUSTbeinstalledthat:
• Is connected from the outlet to a safepoint of
discharge with no intervening valve.
• Allowscompletedrainageofboththevalveandthe
discharge line.
• Isindependentlysupportedandsecurelyanchored
so as to avoid applied stress as possible.
• Terminatesfreelytoatmospherewhereanydischarge
willbeclearlyvisibleandisatnoriskoffreezing.
• Is,overitsentirelength,ofapipesizeequaltoor
greater than that of the valve outlet.
 Use only schedule 40 metal pipe for discharge.
(Do not use schedule 80, extra strong or double
strongpipeorconnections.)DONOTCAP,PLUG
OROTHERWISEOBSTRUCTDISCHARGEPIPE
OUTLET!Ifdischargeispipedupward,acondensate
drain must be provided in the elbow below the vertical
pipe to prevent condensate from returning into the
valve. Failure to comply with these instructions will
cause a dangerous spray of hot water and steam
that would cause severe personal injury or death.
Connecting to counterflow piping
ApplytherecommendedpipinginFigures4through7onlywhen
connecting to a parallel-flow system. When connecting to a
counterflow system, the boiler steam supply must connect into the
top of the counterflow system header, as shown in Figure 3, below.
Figure 3 Connection to counterow steam piping only
(for parallel ow systems, see page 8)
The piping in Figure 3 applies only to the special
case of counterflow steam systems. Refer to page
8 for parallel flow steam systems. See below.
4 Connect steam piping
Table 4 Recommended pipe sizing
Near-boiler piping
SeeFigures4and5,page8,forrecommendedpipingofboilersizes
OSB-3,-4and-5.SeeFigures6and7,page8,forrecommended
pipingofOSB-6boilers.Thesepipingrecommendationsapplyonly
to connections to parallel-flow one-pipe and two-pipe systems.
For counterflow systems, connect boiler supply and return to
counterflow system header as shown in Figure 3, below. Table 4,
below,givesrecommendedpipesizes.
Boiler
model
number
Riser
pipe size
(Note 1)
Header
pipe size
“H”
(Note 2)
Equalize
pipe size
“J”
A B
OSB-3 2-1/2” --- 2-1/2” 1-1/2”
OSB-4 2-1/2” --- 2-1/2” 1-1/2”
OSB-5 2-1/2” --- 3” 1-1/2”
OSB-6 2-1/2” 2-1/2” 4” 1-1/2”
Notes:
1. Based on ASHRAE Fundamentals Handbook recommendations,
allowing ½ oz. pressure drop at 0 psig.
2. Based on ASHRAE Fundamentals Handbook recommendations,
allowing 2 oz. pressure drop per 100 feet of pipe at 3.5 psig.
Maintain minimum 24” height from waterline to bottom of header.
Note Figure 3, showing the special connection required to a
counterow system.

OSB 2 SERIES Specifications

General

Brand	OSB
Model	2 SERIES
Category	Boiler
Language	English