Slimfit Cylinders | High Recovery Slim Fit Cylinders

Although we had been manufacturing slimmer cylinders for many years, the Building Regulations Part L update in October 2010 which required cylinders to be supplied with thicker insulation prompted us to develop a new range of 'SlimFit' cylinders. The main criteria of these requirements were to greatly reduce the amount of heat loss from hot water storage cylinders whilst retaining the heat and,helping to reduce CO2 emissions. One other key benefit we introduced into these units as standard is a multi-bore high recovery coil designed to heat the unit faster than a traditional coil. In doing so and with the addition of an aqua control thermostat, a quicker heat-up time is achieved and a saving of fuel is attained.

Since October 2010, all replacement vented cylinders have been required to have a heat loss rating so significantly reduced, that we have since had to apply a nominal thickness of 40 to 50mm (as we have always done on our solar cylinders, and heat pump cylinders), 50mm being in excess of the requirements for replacements and the minimum thickness for new build installations. Inevitably, thicker insulation results in a larger diameter and with the restrictions that some airing cupboards impose, we believe that many customers have, and will continue to, benefit from taller, thinner hot water cylinders, as it may be preferable for the increase in overall physical size of the unit to be taken up in the height rather than the diameter.

Manufactured in accordance with British Standard, BS 1566-1 : 2002 and in compliance with Part L of the Building Regulations, these cylinders combine a high performance heating coil (where applicable) with low heat loss, factory applied insulation, to provide a highly efficient and effective way to store and provide domestic hot water. Our polyurethane foam insulation can, in most cases, be applied up to a thickness of 75mm and is the most environmentally friendly type available with an ozone depletion potential of zero and a global warming potential of one. For a more aesthetically pleasing finish, we can offer a metal case.

SlimFit cylinders are available as vented, or Unvented units and can either be manufactured as direct or indirect units. In some cases they can also be manufactured as thermalstores Each unit can come complete with immersion heater(s) and a drain valve.

Matching customers' requirements is particularly important when space is at a premium, so the most common customisation for a hot water cylinder, is the “mixing and matching” of the various heights and diameters that we offer. As additional parts of a Bespoke design, the customer is able to specify a number of options including connection sizes/positions, insulation thickness and the finish of the unit (the metal case finish being the premium option). We can offer design drawings prior to manufacture to ensure that all connection sizes, positions and functions are to the customer's requirements.

SlimFit cylinders are available in a range of heights (from 1100mm to 2000mm) and to the specific diameters listed below (all sizes stated are excluding insulation):

Diameter Options

300mm, 350mm, 375mm, 400mm

Height Options

Variable height from 1100mm to 2000mm

Copper Grading Options

Grade 1 (25mtr Mwh), Grade 2 (15mtr Mwh) and Grade 3 (10mtr Mwh)

Shell Connection Sizes Available

1/2", 3/4", 1", 1 1/4", 1 1/2", 2", 15mm, 22mm, 28mm

Insulation Thickness

35mm to 75mm

Coil Heating Surface (Indirect)

Relative to cylinder size (General Guidance - 25 minute recovery)

Coil Working Pressure (Indirect)

3.5 Bar

3/4", 1", 1 1/4", 1 1/2", 2", 22mm, 28mm

Coil Connection Sizes Available

Standard slimfit units are supplied with compression fittings (22 or 28mm)

*All measurements are taken from the floor to the center of the fitting

300mm Diameter

Height	Diameter	Literage	Cold Feed	Boiler Flow	Boiler Return	Secondary Return
1300mm	300mm	85L	100mm	500mm	100mm	800mm
1400mm	300mm	92L	100mm	500mm	100mm	800mm
1500mm	300mm	99L	100mm	500mm	100mm	1200mm
1600mm	300mm	106L	100mm	500mm	100mm	800mm
1700mm	300mm	112L	100mm	500mm	100mm	800mm
1800mm	300mm	119L	100mm	500mm	100mm	1450mm
1900mm	300mm	126L	100mm	500mm	100mm	800mm
2000mm	300mm	132L	100mm	500mm	100mm	800mm

350mm Diameter

Height	Diameter	Literage	Cold Feed	Boiler Flow	Boiler Return	Secondary Return
1100mm	350mm	95L	100mm	650mm	100mm	950mm
1200mm	350mm	104L	100mm	650mm	100mm	950mm
1300mm	350mm	113L	100mm	550mm	100mm	800mm
1400mm	350mm	121L	100mm	550mm	100mm	800mm
1500mm	350mm	132L	100mm	650mm	100mm	1200mm
1600mm	350mm	141L	100mm	550mm	100mm	800mm
1700mm	350mm	150L	100mm	550mm	100mm	800mm
1800mm	350mm	159L	100mm	1100mm	100mm	1450mm
1900mm	350mm	169L	100mm	550mm	100mm	800mm
2000mm	350mm	178L	100mm	550mm	100mm	800mm

375mm Diameter

Height	Diameter	Literage	Cold Feed	Boiler Flow	Boiler Return	Secondary Return
1100mm	375mm	107L	100mm	650mm	100mm	950mm
1200mm	375mm	118L	100mm	650mm	100mm	950mm
1300mm	375mm	128L	100mm	550mm	100mm	800mm
1400mm	375mm	139L	100mm	550mm	100mm	800mm
1500mm	375mm	151L	100mm	650mm	100mm	1200mm
1600mm	375mm	161L	100mm	550mm	100mm	800mm
1700mm	375mm	171L	100mm	550mm	100mm	800mm
1800mm	375mm	182L	100mm	1100mm	100mm	1450mm
1900mm	375mm	192L	100mm	550mm	100mm	800mm
2000mm	375mm	203L	100mm	550mm	100mm	800mm

400mm Diameter

Height	Diameter	Literage	Cold Feed	Boiler Flow	Boiler Return	Secondary Return
1100mm	400mm	121L	100mm	650mm	100mm	950mm
1200mm	400mm	133L	100mm	650mm	100mm	950mm
1300mm	400mm	145L	100mm	550mm	100mm	800mm
1400mm	400mm	157L	100mm	550mm	100mm	800mm
1500mm	400mm	169L	100mm	650mm	100mm	1200mm
1600mm	400mm	182L	100mm	550mm	100mm	800mm
1700mm	400mm	194L	100mm	550mm	100mm	800mm
1800mm	400mm	206L	100mm	1100mm	100mm	1450mm
1900mm	400mm	218L	100mm	550mm	100mm	800mm
2000mm	400mm	230L	100mm	550mm	100mm	800mm

Glossary

Cylinder height is specified from the base of the cylinder to the highest part or the dome excluding port connections and insulation.

Cylinder diameters are specified excluding port connections and insulation material. Only listed diameters are available. For the total diameter of a cylinder including insulation, use the following formula; Insulation Depth x 2 + Cylinder Diameter = Total Diameter, or to find the replacement cylinder diameter , please refer to our online cylinder calculator.

Nominal 50mm insulation is recommended though custom depth can be specified between 35mm and 80mm

Uninsulated units are available upon request.

Material grade relates to the working head and metal thickness, i.e. distance between the feed tank’s water level, and the draw off point on top of the cylinder. Grade 3 is standard for most properties whereas Grade 1 and 2 are used for higher working heads or for longevity of the cylinder.

This is the top centre connection on the dome of the cylinder, there are a wide variety of connection sizes and its worth taking the time to read our Connection Size List before ordering a cylinder, if you are unsure then the simplest option is to specify the cylinder with 22mm or 28mm connections already attached to the cylinder, avoiding additional costs by having to use tank connectors. If a surrey flange is being used, the requirement of a 1" female connection must be specified.

All female connections are parallel BSP thread and taper fittings must not be used.

The connection size for the top entry immersion heater is 2¼" BSP female. An encoloy immersion is advised for use in hard water areas or for longevity. For particularly aggressive water conditions such as high chlorine or acidity, a titanium immersion heater is advised.

This can be specified rather than the use of a Surrey flange or Essex flange and is generally positioned in the upper part of the cylinder and fitted with an internal air ingress prevention device. All compression fittings come with cap nut and olive, avoiding additional costs of tank connectors.

A secondary hot water return connection is generally specified on systems with long pipe runs to wash facilities. Secondary return circuit provides hot water on demand and avoids wastage of cold water, eliminates dead legs in the system and reduces the risk of legionella. This system must be powered by a bronze circulating pump.

Boiler flow and return are connections that are fed from a heating appliance such as a boiler, wood burner or range type cooker. It is most important to specify 1" or 28mm connections and upwards for gravity flow and return circuits to ensure no airlocks occur within the internal coil of the cylinder (Please specify gravity flow and return in the additional information box if necessary).

The connection port is a ½" Female connection that allows for a screw in pocket that is supplied with the boiler control stat, usually specified as aqua control thermostat. This allows for more accurate control of the water temperature and is more efficient than the traditional strap on type control thermostat.

This is the bottom feed connection on the side wall of the cylinder, there are a wide variety of connection sizes and its worth taking the time to read our Connection Size List before ordering a cylinder, if you are unsure then the simplest option is to specify the cylinder with 22mm or 28mm connections already attached to the cylinder, avoiding additional costs by having to use tank connectors

The connection size for the mid entry immersion heater is 2¼" BSP female. An encoloy immersion is advised for use in hard water areas or for longevity. For particularly aggressive water conditions such as high chlorine or acidity, a titanium immersion heater is advised.

The connection size for the bottom entry immersion heater is 2¼" BSP female. An encoloy immersion is advised for use in hard water areas or for longevity. For particularly aggressive water conditions such as high chlorine or acidity, a titanium immersion heater is advised.

Direct flow and return connections were used with traditional solid fuel appliances in certain regions of the country and were specified with 1" Female or Male connections. They are generally not required anymore unless the cylinder is being replaced for use in an old system.

Direct flow and return connections were used with traditional solid fuel appliances in certain regions of the country and were specified with 1" Male or Female connections. They are generally not required anymore unless the cylinder is being replaced for use in an old system.

Opposite side primaries are generally used in old systems and are very rarely encountered any more, these units can be confusing to determin due to the flow connection being on one side and a return connection positioned on the opposite side.

Self explanatory. Please avoid using a drain with a tapered thread or over packing with PTFE Tape.

This is the position specified looking down from above the cylinder as shown on the 'Plan View', 12 O'Clock being at the rear.

Height

Diameter

Insulation

Material Grade

Hot Water Draw Off

Top Entry Immersion

Shower Outlet

Secondary Return

Boiler Flow & Return

Boiler Control Stat

Cold Feed

Mid Entry Immersion

Bottom Entry Immersion

Direct High Flow Conn.

Direct Low Flow Conn.

Opposite Side Primaries

Drain

O'Clock Position

Capacity Calculator

Uninsulated Diameter Calculator

This calculator is designed to assist the specification of a cylinder by determining the amount of hot water available from a cylinder of a specific size; this can be particularly useful in situations where space for a cylinder is limited.

This calculator is designed to assist the specification of a cylinder by determining the size of the cylinder from it's circumference and insulation thickness; this can be particularly useful in situations where a replacement cylinder is required, but due to the insulation it is difficult to determine the size of cylinder required.

Please note - The final figures are approximate and should be rounded to the nearest standard diameter (375,400,450 etc.)

Tapping Chart

To assist with determining the correct size connection for replacement units or units to fit your current system, we have created a table of external and internal thread sizes.