fig. 515 art. 121 › uploads › 3 › 5 › 5 › 5 › 35558088 › zmerly-imt-prv.pdfimt ’s...

DVGW approvedInlet pressure: max. 25 bar (362,50 psi)

Outlet pressure adjustable between 1,5 bar (21,8 psi) and 6 bar (87 psi)Factory pre-set to 4 bar (58 psi)

Temperature Rating: max 30ºC (86ºF) water;Installation position: any

With Pressure Gauge Connections 1/4on both sides and strainer

Pressure reducing valve

Art. 121SWITZERLAND

Fig. 515

The pressure reducing valve Type 515 is used for reducing pressure in systems with media as given in thespecifications below. It is mainly used in domestic water supply, according to DIN 1988.

The IMT range of pressure reducing valves has been specifically designed for applications that require sub-stantial flow capacity with accurate pressure control. The valves are designed for durability whilst being com-pact and easy to service.The body is manufactured in bronze and the one piece, fully serviceable cartridge in high grade engineeringplastics. The valves have integral, serviceable strainers and include test/gauge points as standard.The valve can be supplied in adjustable and fixed settings over range between 1,5 and 6 bar.The ½”to 2” have one piece replaceable cartridges that can be removed, cleaned and replaced with ease.

21,213,78,65,43,31,8DIN 1988Industriel

in m³/h (at 3m/s) Maximum flow

149,15,83,62,31,3DIN EN 1567Residential

in m³/h (at 2m/s) Maximum flow

SW 75SW 75SW 75585858D (mm)

180176176121123123H (mm)140130105877575l (mm)

240205170135117106L1 (mm)

255220190161143132L (mm) Dimensions in mm

G 2G 1 ½G 1 ¼G 1G ¾G ½A

DN 50DN 40 DN 32DN 25DN 20DN 15 Nominal Diameter

www.imt-ch.com e-mail: [email protected]

SWITZERLAND Sonnenstr. 8-10 • CH-9434 Au • Tel. +41-71-7443971 Fax +41-71-7444421IMT ARMATUREN AGSWITZERLAND

Datenblätter Homepage\515-1114-e.cdr \ Version 2 27.11.2014 \ IMT reserves right to change design, dimensions and/or material specifications without notice.

Design

Application

Art. 121SWITZERLAND

Art. 515Pag. 2

The connection size depends on the required

flow rate capacity. When choosing a pressure

reducing valve, it has to be taken into

consideration that a pressure drop of 1.1 bar

occurs at maximum flow rate. This is the

difference between the static and the dynamic

pressure on the outlet of the pressure reducing

valve. When a defined flow rate is required for a

determined draw-off point, the setting of the

pressure reducer has to be calculated

beforehand. A pressure reducing valve works

without auxiliary energy with very little

adjustment forces. For this reason it reacts

sensitively to impurities. A filter installed

upstream protects the pressure reducing valve.

The special cartridge design allows anymounting position.

The body is made of bronze.

All rubber parts are made of high qualityelastomer. The diaphragm is reinforced and thehigh resistance of the screw cap is due to the

glass fibre reinforced synthetic material.

All synthetic parts getting in contact with waterare approved by the German Public Healthoffice (KTW).

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DVGW approved

Installation position: any

Bronze body

Screw cap of glass fibre reinforced

synthetic material

With pressure gauge connections 1/4"

on both sides and strainer

Strainer

Outlet pressure indicator

replaceable cartridge

The pressure has to be set at static pressure.Loose the safety screw in the adjustment

handle. The requested pressure is set with aflick of the wrist. With the well-contrivedcombined adjustment-display handle, thepressure reducer not only ensures an optimalpressure but also allows to read the set

pressure without an additional pressure gauge.To reduce the outlet pressure, turn theadjustment handle in the direction of the minussymbol (-). To increase it, turn the adjustmenthandle in the direction of the plus symbol (+).

Thanks to the special design of the cartridgesystem the disassembling of the operationalparts of the pressure reducing valve isextremely easy and possible without

disassembling the pressure reducing valve itselfand without using special tools.

Art. 515 with Hose Unions on both sides

Maintenance

Material

Version

AdvantagesInstallation


SWITZERLANDIMT ARMATUREN AG Sonnenstr. 8-10 • CH-9434 Au • Tel. +41-71-7443971 Fax +41-71-7444421SWITZERLAND


Pressure control: solving water system problems The water systems in domestic, commercial and industrial properties can present unique problems and challenges as

plumbing fittings become ever more sophisticated.

The water supply pressure in the UK can vary from 1bar to 20bar (or even higher in some low usage areas). The water

pressure will also tend to vary through the day, for instance at high usage times (typically mornings and late afternoons)

the pressure may drop by comparison with low water usage times (throughout the night, for example), when the pressure

may increase dramatically.

Such periods of high pressure can cause several problems: excessive noise from high flow velocities, water hammer from

quick closing taps or solenoid valves, plus the risk of water wastage is particularly great because higher pressure means

higher flow rates.

The water supply usually enters domestic dwellings beneath the kitchen sink so the first effect of high pressure is often

experienced at that point; when the cold tap is turned on too quickly or too far, this creates a gush of water which hits

the bottom of the sink and bounces back, soaking the user and creating a wet mess!

The best way to control high pressure is by installing a pressure reducing valve. These take a high pressure at the inlet,

then the valve reduces it to a lower pressure at the outlet as desired, under both flow and no-flow conditions.

A pressure reducing valve is a valve which takes a high inlet pressure and reduces it to a lower outlet pressure. When

it

does

this

under

both

flow

and

no-flow

conditions,

the

type

of

control

is

known

as

‘drop

tight’. IMT ’s

pressure

reducing valves use a balanced spring and diaphragm to control the downstream pressure.

This ‘drop tight’ feature is one of the most important criteria for any pressure reducing valves, as this stops the pressure

from ‘creeping’ - a term which is used when an increase in the downstream pressure occurs under no flow conditions.

A valve which will allow this ‘creep’ cannot be known as 'drop tight' or in fact a true pressure reducing valve, as it will

Pag. 3 Art. 515SWITZERLAND




Outlet

Inlet

Valve

Valve housing Strainer

SpringPressureIndicator

Diaphragm

Comb

Pressureadjuster

Valve seat

How do pressure reducing valves work?

eventually allow the pressure to creep up to equal the upstream pressure, which can cause significant problems and

essentially negates the point of using a pressure reducing valve in the first place.

The diaphragm effectively separates all of the water contact parts and the pressure from the water supply away from

the control spring and associated mechanism. The body is then protected from debris by the use of a stainless steel

strainer (as shown in the cutaway drawing below).

Under no flow conditions the downstream pressure puts back-pressure on the seat and diaphragm of the valve, which in turn overcomes the spring pressure. This means the seat moves up, forcing it to seal against the diaphragm, therefore

not allowing the downstream pressure to increase.

Under flow conditions the back pressure against the seat is reduced thus allowing the seat to open and water to flow through the valve.

Inlet Outlet/s closedcausing back-pressure

Valve closed

Strainer

SpringIndicator

Diaphragm

Comb

Inlet Outlet/s open

Valve open

Strainer

SpringIndicator

Diaphragm

Comb

Pressure Reducing Valve in closed position

Pressure Reducing Valve in open position

Pag. 4 Art. 515SWITZERLAND




Unique Cartridge Design

How to size a PRVThis is predominantly based on two different criteria: application and flow rates.

Application describes the type of property the valve is to be used in: whether it is commercial/industrial or a domestic

installation.

Flow rate is the most important factor for sizing a pressure reducing valve. Sizing a valve incorrectly can cause several problems; if oversized the

valve seat may open for a very small flow rate, which may occasionally be acceptable but over a long period of time can result in a wire drawing across

the valve seat. A wire drawing occurs when the valve disc and seat position operate close to the shut-off point of the valve for extended periods of

time. This then means the water flow scores a pathway in the seat material which remains when the valve closes tight to the shut-off position and

allows a little flow and pressure to creep through the valve.

To calculate the flow rate you must work out how many outlets are required

and what the combined maximum flow rate for these will be. You can then use the table to ascertain which size valve is required.

All IIAll \ure IMT reducing pressure valves reducing use a valves cartridge use system. a cartridge The system. cartridge The houses cartridge all working houses all working components of the pressure reducing valves: strainer, spring, diaphragm and seat. The cartridge

format makes servicing or replacement of the valves as simple as possible.

Each pressure reducing valve cartridge can be removed for servicing of the integral stainless steel

strainer, which is situated at the base of the cartridge to protect the seat of the valve. If unprotected,

debris could cause poor flow rates and even hold the seat in the open position thus preventing the

pressure reducing valve from working properly. As all working components are incorporated in the

one-piece cartridge, it continues to ensure that the set pressure is kept whilst servicing is being

undertaken. Other valves may need to be re-commissioned after each service or, if they include

several different components, it is easy for these to be misplaced. The cartridge system means

complete replacement cartridges can be used for maintenance or repair, which minimises site down time and means

only one spare cartridge needs to be held in stock rather than several small components.

Some pressure reducing valves can be extremely noisy and cause annoyance, but each IMT reducing valve has been

checked to ensure that any noise created does not exceed the 20dB limit: this is classed as a whisper on a decibel

scale. Low noise is incorporated within the valve design so they comply with the European standard Class 1 BSEN

1567. The base of the cartridge has been specifically designed so that water will disperse, and thereby minimise noise.

The comb also has a second significant purpose: by dispersing the water passing through the valve it alters the water

flow turbulence, and this in turn reduces cavitations on the body of the valve.

All Reliance pressure reducing valves use a cartridge system. The cartridge houses all working

Pressure Reducing Valve Sizing GuideResidential Building Commercial Building

Size DN Max flow rate Vs Max flow rate Vsl/s l/s

15 0.5 0.520 0.8 0.925 1.3 1.532 2 2.4

40 2.3 3.850 3.6 5.965 6.5 9.780 9 15.3

100 12.5 23.3125 17.5 34.7150 25 52.8200 40 92250 75 139

SWITZERLANDArt. 515Pag. 5

mentioned.either wire drawings or creating noise across the valve, as previously

the valve when the flow rate is lower than normal, without causing

one smaller valve as a bypass thus allowing water to flow easily through

using several smaller size PRVs in parallel may be more practical, or use

for example, if the flow rate is lower at some times than at others then

For larger commercial applications various sizing solutions can be used:


SWITZERLAND Sonnenstr. 8-10 • CH-9434 Au • Tel. +41-71-7443971 Fax +41-71-7444421IMT ARMATUREN AGSWITZERLAND


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