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The Institute of Plumbing
Pre-Fabricated Megaflo Cylinders

See also: DPS Pre-Fabricated Pandora Heat Bank Thermal Store - They do everything that a Megaflo will, but have the added advantages:
1.  Higher pressures (up to 9 bar) allowing better performance to multiple outlets.
2.  DIY installable without the need to notify building inspector.
3.  No annual maintenance requirements.
4.  No discharge pipe.
6.  Immune to build up of limescale in store.

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Pre-Fabricated Megaflo Cylinders cut down on site installation time considerably, and ensure that the basic controls for the hot water and heating are installed, wired and tested to exacting standards.

In addition to the domestic water controls, the unit is fitted with the full array of primary controls required for a sealed system.  Installation of the unit simply consists of pipework connections to the boiler, radiators, mains, water outlets, and drain, with wiring to the boiler, room unit and immersion heaters.  The wiring is simplified by the use of Honeywell Smartfit controls.  Connection to the boiler is made from the fitted junction box, while the room unit operates on 12v and requires only two wire polarity-free connection to the Smartfit control centre.

An added benefit of using a pre-fabricated Megaflo is the assurance of tidy pipework.  One is always at the mercy of the installer when it comes to the way controls and pipework are arranged in a cylinder cupboard.  Time on site is not cheap, and space to work is often limited. Sometimes the results are rushed & untidy. In addition, badly though out pipework can obstruct service engineers access to system components. 

When systems are factory assembled, the advantages of being able to design pipework layouts in advance and put them together with ample working space and the correct tools becomes clear.  Components are located where service engineers can gain easy access.  Pipework is straight, supported and pressure tested, with air vents and drain points located where necessary, and all wiring clamped neatly to the unit.  

Domestic Controls:

Pressure Reducing Valve
Expansion Relief Valve
Pressure & Temperature Relief Valve
Inlet Pressure Gauge
Immersion Heaters

Primary Controls:

Honeywell Smartfit Controls:
Smartfit Electronic Control Centre
Programmable Room Thermostat 
Thermistor Cylinder Thermostat
Flow Controls:
     Y-Plan: 1 x 3-Port Valve
     S-Plan: 2 x 2-Port Zone Valves
Primary Circulating Pump with isolating valves
Automatic Air Vent to coil
By-Pass between boiler flow and return, 15mm lockshield
- option: differential pressure by-pass
Overheat 2-Port Valve
Junction Box
Pressure Relief Valve
Pressure Gauge
Filling Loop
Flexible Hose for connecting to expansion vessel
Primary Expansion Vessel with bracket (supplied loose)
Y & W-Plan Megaflo Cylinders
1 Megaflo Unvented Hot Water Cylinder
2 Honeywell Smartfit Room Unit
3 Cold mains in 22mm
4 Balanced cold supply to outlets 22mm
5 Expansion Relief Valve
6 Tundish
7 Flow to Drain
8 Pipe Support
9 Primary Filling Loop
Connected to pipework with push-fit fittings, allowing rotation joints.
10 Mains Flow into Megaflo 22mm
11 Drain Point
12 Immersion Heater
13 Flow from boiler 22mm
14 Primary Pump Grundfos UPS15-50
15 Smartfit 3-Port Motorised Valve
16 Flow to Heating 22mm
17 2-Port Thermal Isolating Valve Honeywell
18 Flow to Primary Coil 22mm
19 Automatic Air Vent
20 Cylinder Thermostats (Overheat + Smartfit Control)
21 Return from Primary Coil
22 Wiring Centre
23 Pressure Reducing Valve with Pressure Gauge
24 Pressure & Temperature Relief Valve
25 Primary Pressure Relief Valve with Gauge
26 Flexible Hose connector to primary expansion vessel
27 Primary Expansion Vessel 8 litre
28 Wall Mounting Bracket for primary expansion vessel
29 Smartfit Base Unit
30 Domestic Hot Water to outlets

S-Plan Megaflo Cylinders
As Y-Plan with following additions:
15a Smartfit 2-Port Hot Water Valve
15b Smartfit 2-Port Heating Valve
31 Return to Boiler
32 By-Pass 15mm
Shown here as a basic lockshield type.  Also available with automatic differential pressure by-pass
All controls are fitted close to the body of the cylinder.  This reduces the footprint of the units and helps to strengthen the pipe supports.

A Honeywell Smartfit control system provides the latest technology in home control.  Hot water and heating times, room temperature, and cylinder temperature are controlled from a single room unit, without the need for an additional programmer.  Connection to the room unit is made by 12v dc polarity-free 2-pole wiring from the base unit. Full control system diagnostics are provided, along with an automatic commissioning sequence. Wiring connections to the motorised valves & cylinder thermostat stat are made by telephone style connectors, and valve heads are push-fit, cutting down on servicing times.

Other options available include 6 metre head primary pump, Grundfos UPE electronic primary pump, 28mm primary controls, automatic by-pass, fitted immersion heater controller with wiring to immersion heaters, & towel rail connection.

copyright Dedicated Pressure Systems Ltd. 1999