MHS Boilers Alpha Jetstream MD User manual

Assembly, Operating and Maintenance Instructions
Installation
and
User Guide
Alpha Jetstream MD
Cast Iron Boiler
105 - 300 kW
35 Nobel Square Basildon Essex SS13 1LT
01268 591010 / 01268 724064
01/07/04

The Alpha Jetstream MD is a cast iron sectional boiler for pressure jet oil or forced draught
gas firing. The boiler is of the horizontal 3 pass type.
The boilers are able to be utilised as low temperature boilers as described in the Boiler
Efficiency Directive 92/42 EEC
MD series are CE Marked on PIN CE-0645BO119 to
Gas Appliances Directive (90/396/EEC)
Boiler Efficiency Directive (92/42/EEC)
Electromagnetic Compatability Directive (89/336/EEC)
and conforms the requiremets of
EN 303/1: Heating boilers with forced draught burners - Terminology, general
requirements, testing and marking
EN 303/2: Heating boilers - Part 2: Heating boilers with forced draught burners - Special
requirements for boilers atomizing oil burners
EN 303/3: Heating boilers-Part 3: Gas fired heating boilers-Assembly comprising a boiler
body and a forced draught burner
MD series boilers are suitable for central heating and indirect hot water supply at
working pressures not exceeding 4 bars, and working temperatures not exceeding 100 C.
The boiler must never be used for direct water supply.
MD Jetstream Cast Iron Boiler for oil and gas firing
INTRODUCTION

TECHNICAL INFORMATION
Boiler type MD 4 MD 5 MD 6 MD 7 MD 8 MD 9
Number of sections
4 5 6 7 8 9
Product-ID number– Notified body number
86/AT/572 – CE0086
Rated heat output kW
105 144 184 223 262 300
Flue gas resistance mmw
g
wg
4 9 16 20 23 33
Combustion diameter mm
370
chamber depth mm
450 580 715 845 975 1105
Length L mm
744 878 1012 1146 1280 1414
Burner mounting diameter mm
170
dimensions depth mm
115
Return/flow connections DN
65 (2 ½ “BSP M)
Flue gas temperature
o
C
185
Flue connection diameter mm
208
Weight (boiler block) kg
430 510 590 670 750 830
Weight (water content) kg
49 61 73 85 96 108
Flow temperature control
o
C
30 – 90
Natural gas* m
3
/h
11.98 16.5 21.04 25.57 29.97 34.36
Fuel LPG** m
3
/h
8.83 12.16 15.5 18.83 22.07 25.31
Consump. 35 sec oil*** kg/h
9.7 13.35 17 20.7 24.24 27.8
Heat input
to boiler Natural gas, LPG, 35 secoil kW
115 158 202 245 288 329

Jetstream Jetstream is a PATENTED NEW TECHNOLOGY developed particularly to prevent flue
Technology gas condensation in the boiler. It is based on increasing the temperature of cool return
water into boiler & mixing it with hot circulating water inside the boiler.
This is accomplished by a jet effect created by a distribution pipe fixed to the return
connection of the boiler
The cool return water is injected into the boiler via a distribution pipe. This injection results
in a pressure drop at the end of the pipe, creating a vacuum. This vacuum sucks hot
delivery water of the rear section/sections down to mix with the return water
thereby raising the return water temperature. Thus, the main reason
of flue gas condensation in the boiler is eliminated. Also a reverse flow of hot water
in the rear section of the boiler protects the section against excessive thermal shocks.
The Alpha Jetstream MD will
operate without condensation
providing the minimum return
water temperatures are
observed:
Fuels Lowest return temperatures
(°C)
Naural gas, LPG 35
Light oil 25
TECHNICAL INFORMATION

Fluegas resistance
Efficiencies
Values given according to average boiler water temperature of 70 C
Flue gas
temperatures
Values given according to average boiler water temperature 70 C, ambient temperature
20 C
TECHNICAL INFORMATION
Flue gas resistance (mbar)
1
00%
l
oad
75% load
50%
l
oad
LOAD
LOAD
Combustion
Overall

Oil Supply MD series boilers can only be fired with liquid fuels having following specifications:
Kerosene viscosity at 20 C: 1.2 cSt or viscosity at 100 F: 28 Second *
Light oil (EL) viscosity at 20 C: 4- 6 max cSt or viscosity at 100 F: 35 Second
Gasoil (D) viscosity at 20 C: 4- 6 max cSt or viscosity at 100 F: 35 Second
*Burners suitable for Kerosene have limited availability and range
Any failure due to lack of technical precautions, firing with fuels
not suitable for boilers, and operation without taking recommendations given further in
this manual into consideration, will always be the responsibility of the end-user.
A single pipe oil supply with oil at a slight positive pressure is generally required though
the burners own oil pumps can provide some lift of the oil depending on the volume flow
and the lift required. For dual fuel burners a two pipe oil supply system is generally
recommended unless the burner is fitted with an oil pump clutch. An oil filter and
isolating valve should be provided and the burner connected to the oil supply with a
flexible oil hose. The hose and filter are generally supplied with the burner.
Gas Supply The local gas supply authority should always be contacted at the design state to ensure
an adequate supply is available. An existing service pipe must not be used without prior
consultation with the local gas supply authority and the supply must be made through a
suitable meter.
The matching of burner model, burner and gas train size must be carried out in
accordance with supplied inlet gas pressure and fuel type to be fired. When sizing the
burner and gas train, all pressure losses inside the boiler, burner and gas train, and in
piping from burner inlet to main gas meter must always be taken into consideration.
Burne
r
MD boiler must be fired only with a CE APPROVED BURNER which is according to
Gas Appliance Directive and tested according to EN 676. MHS Boilers will not be
held responsible for any damage or failure due to use of a non approved burner.
It is not recommended to increase the diameter of hole in the middle of front refractory to
make the mounting of burner easier. If there is a space left between the hole in front door
refractory and burner tube after mounting, this space must be packed with rock-wool or
ceramic-fibre based insulation material to improve heat insulation. Otherwise, further heat
loss may result in damage to the front door.
Should the diameter of burner head be greater than that of the hole in front door refractory,
the diameter of the hole must be increased so that the burner passes smoothly through
the hole. Front refractory must be protected against breaking during mounting and
dismounting of burner.
TECHNICAL INFORMATION

Water side The fully watercooled sections are joined by cast iron conical nipples, and distribution
of boile
r
pipe fitted to the return ensures even the temperature distribution throughout the boiler.
The cast iron sections are to BS.1452 Grade 200 with 7 mm wall thickness. Return and
flow connections to heating system are provided by stub-pipes at the rear of the boiler.
Under no circumstances should the boiler be fired when its circulation volume is less than
a recommended minimum volume calculated according to the following formula:
The following table provides hydraulic resistances at various water volumes relativ to boiler
Dt flow/return. The difference between flow and return temperatures of the bolier should
not be greater than 20 C to provide convenient operating conditions in the boiler:
Boilers must be connected to a chimney by using the shortest possible connector which
should be insulated by mineral wool or similar material. The flue connector must rise at
Flue design an angle from boiler to chimney of not less than 10º. Conditions creating high resistance
and chimne
y
to gas flow should be avoided in the flue connector. The flue outlet of the boiler should
installation not support the weight of chimney.
The draft generated by the chimney should be capable of overcoming the chimney
resistance.
Chimney calculations should be carried out in compliance with the standards. Conditions
of existing chimney should be checked and proper precautions should be taken against
excessive cooling and condensation. Chimneys should be lined if necessary
Positive draught conditions must be avoided
Negative draught conditions should be contained within -3 mm wg. (30Pa) for optimum
boiler performance.
The following table shows typical flue gas volumes at gross flue temperature of 190°C and
ambient air temperature of 20°C.
146.9 528.9MD9 300 139.9 503.8
109.2 393.1
MD8 262 122.2 439.9 128.3 461.9
MD7 223 104 374.5
70.5 253.9
MD6 181 85.8 309 90.1 324.4
MD5 144 67.2 241.8 51.4 185.1
kW g/sec kg/h g/sec
MD4 105 49 176.3
TECHNICAL INFORMATION
Boiler type Output Flue gas volume
Light Oil
C02=13% Natural gas G20
C02=9.5%
kg/h
l/s
252
OutputkW =
∆t=10
o
C ∆t=15
o
C ∆t=20
o
C
Type
Minimum Circulation Water Flow Hydraulic Resistance Water Flow Hydraulic Resistance Water Flow Hydraulic Resistance
l/s l/s kPa l/s kPa l/s kPa
MD 4 0.41 2.5 8.1 1.66 3.7 1.25 2.2
MD 5 0.58 3.42 16.0 2.28 7.2 1.71 4.1
MD 6 0.75 4.38 15.5 2.92 6.8 2.19 3.9
MD 7 0.88 5.33 20.6 3.53 9.2 2.65 5.2
MD 8 1.05 6.23 29.5 4.15 13.2 3.13 7.5
MD 9 1.19 7.14 39.0 4.76 17.4 3.57 9.8

Boiler room The installation must be arranged in accordance with Mandatory Regulations and Codes
arrangement of Practice. The following sketch shows the recommended minimum dimensions of
clearance around the bolier for servicing and maintenance
Boiler room should not be used for any other applications, floor should always be kept dry
and clean. Any obstacles in front of ventillation openings must be avoided. The boiler room
air openings must conform to the requiements of BS 5410 Pt2 or BS 6644 as appropriate
Never drain the system unnecessarily.
Follow instructions for periodic cleaning and maintenance operations whose procedures
are given further in this manual.
The boilers must be installed onto a smooth level surface of non-combustible material.
A steel baseframe and a 50 mm thick mineral wool mat to insulate the underneath of the
boiler are included in the supply. A raised plinth shall be used. It is recommended that
the plinth be at 150 mm high and sized to the dimensions of casing of the boiler given as
in the following table:
PREPARATIONS BEFORE ASSEMBLY
Recommended dimensions of plinths (mm)
Type
MD4 MD5 MD6 MD7 MD8 MD9
Width 830
Length 775 905 1035 1165 1295 1425
Height 150

Water The system design must ensure a flow rate consistant with the output of the boiler at
Circulation a temperature rise not normally exceeding 20ºC (25ºC Max).
System Due to the Jetstream technology employed in the boiler, the boiler may be operated at
continuous low return water temperatures without condensation and without the need for
back-end temperature protection measures, providing the minimum temperature limits
detailed in the technical data are observed. This allows variable flow temperatures to be
utilised (direct-on-boiler weather compensation) without the need for variable temperature
mixing valves. This simplifies the installation and ensures peak operational efficiency from
the boiler.
Should the system be operated at temperatures below than those mentioned above,
then a thermostatically controlled pumped by-pass (shunt pump) should installed
between the flow and return pipes to raise the temperature of the return water.
This is particularly important when firing with gas because of the higher dewpoint
temperature of gas products of combustion.
Water levels should be checked regularly and any leakages corrected in order to keep
system water make-up to a minimum, because excessive make-up will lead to scale
deposits forming in the boiler waterways causing local overheating and damage to the
boiler sections. Where there is doubt as to the quantity of water make-up, a water meter
should be fitted. If a system is known to lose water continuously, or be heavily
contaminated with dirt or sludge, then consideration should be given to installing a plate
type heat exchanger to separate the boiler from the damaging effects of the old system.
Boiler water systems should be thoroughly flushed and cleaned before a new boiler is
installed and system water should be treated with a scale and corrosion inhibitor
and best practise observed. The system should include strainers and consideration should
be given to fitting sludge traps if conditions warrant them.
The system can be either open vented or pressurised.The system must be fitted with
appropriately sized safety relief valve, reference to BS5410 Part2 or BS6644 will give
Safety o
f
guidance on selection.If the system is open vented then an appropriately sized open pipe
water must be installed from the flow pipe adjacent to the boiler to run by the shortest possible
circulation direct route to terminate over the feed and expansion cistern. The boiler flow and return
system pipes should be fitted with isolation valves taking care to ensure that the safety relief
valve is installed onto the flow pipe between the boiler flow connection and the flow
isolation valve.
An altitude guage should be installed onto the flow pipe at the same level as the top of
of the boiler and marked with the minimum water level/pressure following first filling
of the system.
In the case of a sealed and pressurised heating system, an appropriately sized and
charged expansion vessel should be installed in conjunction with an automatic
water make up unit (pressurisation unit).
Filling the System . Non Domestic (other than in-house) fluid category 4
For category 4 systems, the approved method of filling must comprise the following
components arranged as shown: Control valve on the mains cold water pipework,
Strainer,Verifiable backflow prevention device with Reduced Pressure Zone (RPZ valve)
incorporating a type BA air gap, Tundish, Control valve on heating system.
PREPARATIONS BEFORE ASSEMBLY

Requirements
on filling The quality of the filling and any refilling water is important and must be of
water sufficient quality to maintain the following requirements:
pH 8 - 9.5
Maximum hardness between 8 and 12 grammes of calcium carbonate per 100
litres of water.
We strongly recommend that the system is chemically cleaned and then
dosed with a good quality corrosion and scale inhibitor before the boiler is
first fired. The boiler is guaranteed against material and manufacturing defects
however, failures or problems brought about by inadequate water quality are
expressly excluded from any guarantee or warranty and will render the
guarantee on the product void.
PREPARATIONS BEFORE ASSEMBLY

MD Jetstream MD boilers are delivered unassembled and consists of the following parts:
Delivery Consignement
1. Boiler block: A block of sections, smokehood and front door is delivered on a pallet for
easy shipping. The sections must be assembled in the boiler room. Refractories for
combustion chamber insulation are mounted on the rear section at the factory. Smokehood
is fixed to rear section. Boiler block contains the materials used in the assembly of the
block such as nipples, fiberglass ropes, flow and return connections...
2. Casing/insulation box: This box contains all casings and baseframes (if required)
together with the insulation blankets. Retarder sets and control panel are also
supplied in this box.
Delivery method of Alpha Jetstream MD boilers.
ASSEMBLY INSTRUCTIONS

Assembly o
f
Numbers in the brackets refer to position numbers in the exploded drawing.
Boiler Body 1. Place steel profiles (19) which are used
as baseframes of the boiler parallel to each
other as shown in the figure at the l/h side.
The distance from the baseframes vary
from 320 mm to 970 mm as the number of
sections vary from 4 to 9.
2. Start assembly with rear section (1), clean all rope grooves on the section using a wire
brush. Clean nipple ports and nipples using cloth and paraffin. Apply adhesive to the rope
grooves on the front side of the section. Fix continuous lengths of 10 mm rope (5) in each
groove starting with the outer groove as shown in following picture. Tape each end of rope.
Apply jointing compound onto nipples, and place nipples (4) squarely in each nipple port
and, using a wooden mallet, lightly tap nipple into the port to secure.
3. Take an intermediate section (2) and prepare the section as described above. Place
rear section at the end of baseframes. With its unroped side facing towards the rear, fit
the intermediate section squarely onto nipples of the rear section and secure by using
a wooden mallet. Ensure that the rope on the rear section remains in correct position
NOTE: Do not fix rope into the grooves of the side of the intermediate section facing the
rear section. Likewise, apply the same procedure for the following sections applying one
rope between two sections.
4. Continue boiler assembly repeating the same procedures with the other sections.
Apply "Compression Tools" passing them through bottom and top nipples as shown in
following figure, and accordance with the table headed "Usage of Compression Tools",
until the rope between each section is firm. The gap between each section should be
3-4 mm.
ASSEMBLY INSTRUCTIONS
320/450/580/
710/840/970
Rear section
Intermediate section
Upper staybolt
Front section
Ni
pp
le
Co
p
ression tools
Usage of compression tools
Model First
application
(Number of
sections)
Second
application
(Number of
sections)
MD4 4
MD5 3 5
MD6 3 6
MD7 4 7
MD8 4 8
MD9 5 9

After assembly of all sections, apply compression tools for the block. Before loosening
fit upper and lower staybolts (7,8) using M12 nuts (9) and washers (10).
5. Fit studs M12x45 (20) to return and flow connections of the rear section.
Do not use excessive force to tighten the nuts up on the staybolts, from 48 to 54 Nm
(35 - 40 lbf/ft) torque is recommended.
Hydraulic test Fit plugs (147) to top and bottom of front section. Fit 1/8" plug (109) supplied in boiler
block into 1/8" hole on top of the rear section (with control panel this hole is not used).
For 1/2" and 3/8" instrument tappings on top of the rear section, use
1/2" and 3/8" pockets for bulbs supplied with standard control panel or suitable plugs.
Use hydraulic test apparatus for the boiler. Fit bottom test flange with two globe valves
and test gasket to return connection. Fit blank flange and the other test gasket to flow
connection as shown for MD boiler in the following figure.
Connect a hydraulic test set to one of the globe valves on test flange fitted to return
connection. Fill the boiler with water by connecting the other valve on test flange to the
water circuit. Meanwhile, release the air left in the boiler via bulb pocket holes on top of
the rear section. When water comes out of the holes, refit the bulb pockets . Turn the
valve connected to circuit off and turn the other valve connected to the hydraulic test set
on. Pressurise the boiler via the pump on the test set until the pressure gauge
reaches the test pressure.
Hydrostatic test should be carried out at a pressure of 1.5 x P; where, P is the
maximum operating pressure of boiler. Duration of test should be at least 30 minutes.
The hydrostatic test must always be carried out before boiler being jacketed or heat
insulated, and connected to the heating circuit.
After hydrostatic test, "Boiler Assembly Certificate" should be filled in and signed by the
erector/installer. In order for warranty terms of boiler to be valid, make sure
that this certificate is completed, signed, and sent to MHS. We recommend that you
ask for a copy of assembly certificate from erector/installer.
ASSEMBLY INSTRUCTIONS

6. Fit distribution pipe (22) with gasket (25) to return connection. Fit flanged stubpipes
(21) and their gaskets (25) to flow and return connections. Fit nuts and washers to the
35 mm threaded end of M10x105 studs (145), screw and lock the studs into the corner
positions of rear section.
When placing the distribution pipe into the return connection, ensure that the white arrow
on the flange of the pipe points upwards (The axis of the pipe should be off -centre towards
the bottom of the square flange). Wrong position of the distribution pipe will result in
incorrect temperature gradient and higher condensation rate in the boiler.
ASSEMBLY INSTRUCTIONS

Jacket assembl
y
1. Fit cast iron hinges(143) used for carrying front door onto front
section using 2 M8x30 setscrews (142) for each hinge.
Before assembly of front door (131), first decide the side of hinging
(for LH or RH opening). Screw hinge pins (141) into threaded holes.
Screw a M16 nut (49) onto each hinge pin as shown in figure below
left.
Hang the front door on M16 nuts. Position the front door up or
downwards by losening or tightening the M16 nuts.
2. There are two types of retarders. One is the second pass retarder (95) or (99) and the
other is the third pass retarder (for 4,5,6,7 sections) (97). Second pass retarders consist
of two stainless steel bladed modules (95 and 99). The modules are combined together
according to following table for preparing second pass retarders. Retarders are placed into
second and third flue gas passages of boiler as shown in following pictures:
In case of light or medium fuel-oil firing, the second pass retarders should not be used,
and input to boiler should be slightly reduced to values given in technical informations.
3. Fix front door to front section using four x M10x30
setscrews(136) and 10.5 washers(137).
4. Loosen the nuts on the front end of the upper staybolts(8) and
fit upper casing support (155) with its bend facing towards the rear
section. After mounting the front support sheet, ensure it to be
aligned parallel to the floor.
ASSEMBLY INSTRUCTIONS
Second pass retarder
modules MD4 MD5 MD6 MD7 MD8 MD9
2 bladed module 2 1
3 bladed module 1 2 2 2 2

5. Place boiler body insulation (117) squarely on top of boiler block. After placing the
insulation, secure both ends of the insulation blanket to lower staybolts by using four
retaining springs(156).
6. Fit left and right rear insulation panels(157) to smokehood (11) and secure by pushing
onto the M10x105 studs (145). Fit base insulation panel (93) underneath the boiler block.
7. Fit side casings (148,149) passing M10x105 studs (145) through the holes on the return
folds of the casing, hanging the front edges of casing onto the upper casing support (155)
and fixing the front lower end of the casing to the free end of the lower staybolt (7). Fit side
casings by M10 nuts (153) and washers (152) to the M10x105 studs (145), by M6 set
screws to the front upper casing support and by M12 nuts and washers to the lower
staybolts.
8. Fit the top casings (163,164) onto the side casings by special pins (162,161).
9. Fit the rear panel by self tapping screws (160) to the return folds of the side casings.
The rear panel is in two parts - upper (158) and lower rear (159) panels.
ASSEMBLY INSTRUCTIONS
M10x105 studs
Insulation
springs

Electrical 1. Before assembly of control panel on top casing front piece (163), pass the capillary
Installation tubes of the panel through the large hole on the top casing. Fix control panel (110) onto
the top casing using 4 self tapping screws S 4.8x9.5
2. Place the bulbs of the control and safety thermostats into 1/2" pocket and the bulb of
boiler thermometer into 3/8" pocket fitted on the rear section routing all the capillary
tubes underneath top casings but on the top side of the insulation blanket. Secure the
bulbs of the instruments into the pockets with the clips supplied.
3. Fit top casing front panel mounted with the control panel onto the boiler.
4. Pass electrical wiring through prepared hole in rear of side casing and route cables into
control panel making sure that cables are on the top side of the insulation. Make
electrical connections in accordance with Mandatory Regulations and Codes of Practice,
and follow burner manufacturers instructions.
The main electrical supply should be taken from a local fused isolator having a minimum
contact separation between the poles of 3 mm, and taken to the phase, neutral and earth
connection in the boiler control panel.
The burner connection cables from the boiler control panel should be routed through the
top and side panels, then shall pass under side panel to the burner, ensuring that the
cables are placed on the outside of the boiler insulation blankets.
All cables should be suitable for a service temperature of 100 C and a load of 10 Amp, and
have a minimum cross sectional area of 1,5 mm2.
This appliance must be earthed.
Control panel
Detail of the P3 climatic control panel can be found in the separate literature for this item.
ASSEMBLY INSTRUCTIONS

ASSEMBLY INSTRUCTIONS