resideo Braukmann NK300S Boiler Feed Combination Installation Guide
- June 6, 2024
- resideo
Table of Contents
Braukmann
NK300S Boiler Feed Combination
APPLICATION
The Resideo Braukmann NK300S Boiler Feed.
The combination serves as a boiler fill valve used in closed-loop heating
systems. The NK300S is a (re)filling combination valve that contains an
integrated pressure reducing valve, strainer, double-check backflow preventer
with air vent (to protect potable water supply against backflow of heating
water into supply pipe), two shut-off ball valves, pressure gauge, and
conveniently located test ports for easy inspections and check out.
SPECIFICATIONS
Model: NK300S Boiler Feed Combination
Model Numbers: NK300S-100 (includes sweat and threaded connections) NK300S-
100UP (includes union press-fitting connections)
Medium: Water
Regulator Mechanism: Fiber-reinforced EPDM diaphragm
Filter Mechanism: Stainless steel fine filter mesh Inlet Pressure (Maximum):
150 psi (10.3 bar)
Inlet Pressure (Min): 30 psi (2.0 bar)
Outlet Pressure Range: 10 psi – 58 psi (0.7 bar – 4.0 bar)
Outlet Pressure: Factory set at 15 psi (1 bar) Pressure setting tolerance: ± 4
psi.
Differential: 14.5 psi minimum (inlet to outlet)
Fluid Temperature (Maximum): 180 °F (82 °C) according ASSE 1081
Ambient Temperature Range: 33 °F to 140 °F (1 °C to 60 °C).
Pressure Gauge: 0-60 psi @ max temp 140°F (60°C)
Connection size: 1/2” NPT, Sweat, or Union Press
Connection size discharge: 1/2″ NPT
INSTALLATION INSTRUCTIONS
Connection size test ports: 1/4” NPT
Installation position: Horizontal pipework with discharge connection directed
downwards
Max. flow rate: 16 gpm (60 l/min) @ 22 psi (1.5 bar) pressure fall-off
Approvals: ASSE 1081 Listed
The function of the backflow preventer
The backflow preventer is a safety device in accordance with ASSE 1081 to
protect the quality of potable water against back pressure, backflow and back-
siphonage of non-potable water from plants and connected equipment.
The backflow preventer is separated in three chambers (inlet, middle, and
outlet chamber).
If no water is drawn from the downstream system, the backflow preventer is in
a normal position. The up-and downstream check valves and the discharge valve
are closed.
If water is drawn from the downstream system, the backflow preventer is inflow
position. The check valves up and downstream are opened and the discharge
valve is closed.
The backflow preventer changes to shut-off position (back pressure) if the
differential pressure between the middle- and inlet chamber falls under 2 psi
(0.14 bar).
The check valves are closed and the discharge valve is opened.
The function of the pressure reducing valve
The pressure-reducing valve reduces the inlet pressure to the desired set
pressure on the outlet side. The pressure-reducing valve works according to
the force comparison principle.
The force of a diaphragm operates against the spring force of the regulating
valve. If the outlet pressure and therefore diaphragm force fall because water
is drawn, then the greater force of the spring causes the valve to open. The
outlet pressure then increases until the forces between the diaphragm and the
spring are equal again.
The inlet pressure has no influence on the regulation of the pressure-reducing
valve. Inlet pressure fluctuation does not influence the outlet pressure, thus
providing inlet pressure balancing.
In order to prevent an uncontrolled refill of the heating system, the shut-off
valve must be closed after the filling procedure.
The refilling combination consists of:
- Shut off valve, up-and downstream.
- Dual check backflow preventer with discharge connection, valve cartridge (incl. integrated check valve and discharge valve, upstream), integrated strainer upstream (mesh size approx. 200micron), check valve downstream, and three test points.
- Pressure reducing valve with valve insert (incl. diaphragm and valve seat), spring bonnet (incl. adjustment screw), adjustment spring, and pressure gauge.
INSTALLATION
When Installing this Product…
-
Follow the installation instructions.
-
Use and install the appliance.
• According to its intended use.
• In good condition.
• With due regard to safety and risk of danger- according to local codes & standards. -
Note that the appliance is exclusively for use in the applications detailed in these installation instructions. Any other use will not be considered to comply with requirements and would invalidate the warranty.
-
Please take note that any assembly, commissioning, servicing and adjustment work may only be carried out by authorized persons.
-
Immediately rectify any malfunctions which may influence safety.
-
Press connections, use press tools and installation practices compatible with Viega systems.
Assembly
Installations Guidelines
It is necessary during installation to follow the installation instructions,
to comply with local requirements, and to follow the codes of good practice.
- Install in horizontal pipework with discharge connection directed downwards.
- The installation may not take place in areas or ducts where poisonous gases or vapors may be present or where flooding can occur.
- The installation environment should be protected against frost and ventilated well.
CAUTION
The device shall not be installed in a concealed or inaccessible location or
where the venting of water from the device during its normal functioning may
be objectionable.
-
The installation location has to be easily accessible:
— Simplified maintenance and cleaning.
— Pressure gauge at the pressure-reducing valve can be read easily. -
Provide a straight section of pipework of at least five times the nominal valve diameter after the pressure-reducing valve.
-
The refilling combination has an integrated strainer – no separate strainer necessary.
— Refilling combination is protected against malfunction and corrosion damage resulting from the ingress of foreign bodies, e.g. welding beads, sealing materials, metal cuttings, and rust. -
The national installation codes & regulations must be observed during the assembly.
Assembly instructions
NOTES:
— To avoid stagnating water the refilling combination (NK300S) must be
attached as directly as possible to the service pipe!
— The rules of the drinking water regulation must be considered during the
assembly! Fasten the plastic sealing plugs manually only (without tools)
-
Thoroughly flush pipework.
-
Install refilling combination.
• Install in horizontal pipework with discharge connection directed downwards.
• Note flow direction (indicated by arrow).
• Install without tension or bending stresses. -
Provide a straight section of pipework of at least five times the nominal size after the refilling combination.
-
Attach drain pipe to discharge connection following local codes & standards.
Start-up
Filling up the system
1. Slowly open shut-off valves on inlet and outlet. Due to casual fluctuation
of pressure during system fill up, dripping water at the discharge valve can
occur.
Setting outlet pressure
The pressure-reducing valve is set to 15psi (1bar) by the factory. The
pressure of the supply system should be at least 30psi (2bar) above the set
outlet pressure.
-
Close shut off valve on inlet and outlet.
-
Release pressure on the outlet side.
• E.g. loosen the pressure gauge.
• Afterwards screw-in pressure gauge again. -
Slacken tension in compression spring.
• Turn adjustment handle counterclockwise (-)
until it does not move anymore. -
Slowly open the shutoff valve on the inlet.
-
Turn the adjuster knob until the pressure gauge shows the desired value.
-
Slowly open the shutoff valve on the outlet.
MAINTENANCE
Maintenance of the backflow preventer must be carried out by authorized
personnel!
Inspection
NOTES:
— Frequency: Every 6 months (depending on local operating conditions).
— To be carried out by an installation company.
Inspection with a test control unit and maintenance set (see accessories).
Testing pressure reducing valve
-
A close shutoff valve on the outlet.
-
Check outlet pressure on the pressure gauge when no flow is occurring.
• If the pressure is increasing slowly, the valve may be dirty or defective. In this instance, carry out servicing and cleaning. -
A slowly open shutoff valve on the outlet.
Testing discharge valve
NOTE: Quick test for the discharge valve:
Lower the inlet pressure: if the discharge valve opens (drops) and water
drains from the valve, the valve is functioning.
Testing outlet check valve.
- Close the upstream shut-off valve (1).
- While monitoring the discharge valve outlet (2) loosen the plug (3) carefully and partly only! This will empty the water between the shut-off valve and the backflow preventer.
- When the outlet check valve works properly only a small amount of water is drained through the discharge valve outlet (2).
- In case of water continuously drops/flows out of the discharge valve outlet (2) the outlet check valve may be cleaned or replaced (see instructions on how to replace).
Maintenance
NOTE: We recommend a planned maintenance contract with an installation
company.
In accordance with local codes & standards, regular maintenance must be taken.
Frequency: To be carried out by an installation company, depending on local
operating conditions.
Pressure Reducing Valve insert
-
Close shut off valve on inlet and outlet.
-
Release pressure on the outlet side.
• E.g. loosen the closing plug 1.
• Afterwards screw-in closing plug again. -
Slacken tension in compression spring.
• Turn adjustment handle counterclockwise (-) until it does not move anymore.
CAUTION
There is a spring in the spring bonnet. It may cause injuries if the spring is derailing.
Make sure tension in the compression spring is slackened! -
Unscrew spring bonnet.
• Use spanner. -
Remove slip ring.
-
Remove valve insert with a pair of pliers.
-
Check that the sealing ring, edge of the nozzle, and slotted ring are in good condition and if necessary replace the entire valve insert.
-
Reassemble in reverse order.
-
Set outlet pressure.
Maintenance and cleaning of cartridge insert
CAUTION
Do not use any cleaners that contain solvents and/or alcohol for cleaning the
plastic parts, because this can cause damage to the plastic components – water
damage could result. Cleaning agents can lead to water damage! Detergents must
not be allowed to enter the environment or the sewerage system!
-
Close shut off valve on inlet and outlet.
-
Remove blanking plugs.
-
A backflow preventer is released.
-
Remove cover from cartridge insert.
-
Remove cartridge insert and strainer.
-
Remove the strainer from the cartridge insert.
-
Clean or replace strainer and cartridge insert.
WARNING
Do not dismantle the cartridge insert in individual parts! -
Reassemble in reverse order.
• Push down the cartridge insert till it snaps in. -
Check operation.
Outlet Check valve
- Close shut off valve on inlet and outlet.
- Remove blanking plugs.
- A backflow preventer is released.
- Remove valve insert of pressure reducing valve acc. to “Pressure Reducing Valve insert” on page 3.
- Replace check valve.
- Mount valve insert of pressure reducing valve ACC. to “Pressure Reducing Valve insert” on page 3.
- Check operation.
DISPOSAL
- Dezincification-resistant brass housing.
- Discharge connection, valve cartridge, valve insert, and spring bonnet in high-grade synthetic material.
- Fiber-reinforced EPDM diaphragm.
- Seals in NBR and EPDM.
- Spring steel adjustment spring.
- Stainless steel fine filter mesh.
NOTE: Observe the local requirements regarding correct waste recycling/disposal!
TROUBLESHOOTING
Problem | Cause | Remedy |
---|---|---|
No or too small water flow rate | The refilling combination is not fitted in | |
the flow direction | Fit refilling combination in the flow direction (note |
direction of the arrow on housing)
Ball valves up- or downstream of refilling combination are not fully open|
Open shut off valves fully
Pressure reducing valve is not set to the desired outlet pressure| Set outlet
pressure
The integrated strainer is contaminated| Clean strainer
The discharge valve opens without reason (no fluctuation of inlet pressure)|
Nonreturn valve upstream or discharge valves are contaminated| Remove
cartridge insert and clean or exchange it
The discharge valve does not close| The discharge valve is contaminated or
faulty| Remove cartridge insert and clean or exchange it
Water is escaping from the spring hood| Valve insert diaphragm damaged|
Exchange valve insert
The outlet pressure set does not remain constant| Valve insert, sealing ring
or edge of the nozzle is contaminated or worn| Exchange valve insert
SPARE PARTS
Table 2.
No. | Description | Dimension | Part No. |
---|---|---|---|
1 | Cartridge insert complete | 1/2″ | 903733 |
2 | Check valve | 1/2″ | 904182 |
3 | Valve insert complete (without sieve) | 1/2″ | DO4FMA-1/2 |
4 | Sealing ring set (10 pieces) | 1/2″ | 901443 |
5 | Blanking plug | ||
with 0-ring R1/4″ (5 pcs.) | S06K-1/4NPT | ||
6 | Pressure gauge | 904181 |
Ranges 0 – 87psi (0-6bar) bar
Resideo Technologies, Inc.
1985 Douglas Drive North, Golden Valley, MN 55422
1-800-468-1502
33-00339EFS—05 M.S. Rev. 02-21 | Printed in the United States
www.resideo.com
© 2021 Resideo Technologies, Inc. All rights reserved.
This product is manufactured by Resideo Technologies, Inc. and its affiliates.