Table of Contents
1. Description of product and function
1.1
The NOREVA non-return valve range
1.2
Correct use
1.3
Transport and storage
1.4
Installation in the pipeline - Assembly
2. Servicing and maintenance
2.1
Servicing and maintenance
2.2
Spare parts
2.3
Replacement of spare parts
2.3.1
Disassembly of Non-Return valve NRV-Z /ZK / ZSK / K
2.3.2
Assembly of Non-Return valve NRV-Z /ZK / ZSK / K
2.3.3
Disassembly of Non-Return valve NRV-B / BK
2.3.4
Assembly of Non-Return NRV-B / BK
2.4
Incident during operation / Corrective action
NOREVA GmbH Hocksteiner Weg 56 D-41189 Mönchengladbach Tel.: +49(0)2166-12686-0 Fax: +49(0)2166-12686-55/66 Email: info@noreva.de Internet: www.noreva.de
Non-return valves are used wherever reverse flow of the conveyed fluid is to be prevented. They are suitable for all liquid and gaseous media and are heat-resistant thanks to the exclu-sive use of metal materials and non-corroding internal components.
1. Description of product and function
NOREVA non-return valves are produced in conformity to PED/97/23/EC and are tested at the manufacturer's works in accordance with DIN EN 12266 for mechanical strength and tightness.
ATEX Directive 94/9/EC does not apply to NOREVA non-return valves.
Typical applications include, for example, oil pipelines, iron and steel plants, chemicals plants, water recovery, pumping stations, water distribution systems, power generation plants, gas compressor stations, seawater desalination plants, etc.
These valves provide smooth and shock-free closure within fractions of a second thanks to their short closure paths and low moving masses.
CAUTION!!!
Hot fluids present a danger of burns, customers must thermally insulate valves!
1.1 The NOREVA Non-return valve range
Our range of products can be found in our catalogue and on our Internet site
Thanks to their design and construction, NOREVA non-return valves are used in the most diverse range of industries.
1.2 Correct use
NOREVA-non-return valves are designed for following application:
Ambient temperature: -50°C to +50°C
Admissible working temperature: -196°C to +500°C
The operating data can be taken from the name plate for specific application.
• Our non-return valves are produced specifically in accordance with the
cus-tomer's specifications and for his application, and may be used only
• Use for other operating data and/or for installation locations or services is not
permissible without the manufacturer's agreement.
for this purpose.
• The operator/user must implement provisions to eliminate valve flutter during
operation.
• The conveyed fluid or gaseous media must be at a temperature not less than
20% remote from its auto ignition temperature.
Valves must not be suspended using lifting tackle (S-hooks) inserted into the flange borings, nor may they be rolled on the flanges, since both methods will damage the corrosion protec-tion.
1.3 Transport and storage
A non-return valve with no suspension lugs must be handled and transported using belts slung around both flange necks and attached to the lifting equipment. The valves can also be equipped with threaded holes (for ring-bolts) and/or suspension lugs for the purpose of
handling and transportation.
The non-return valve must be secured for transportation on a wooden pallet using wood packing and fixing straps.
The stability of the non-return valves during transportation and storage must be ensured by positioning the valves on their flanges.
The direction-of-flow arrow must always point upward.
Figure 2
Fixing tape Wood beams
Remove the packaging materials. The pipeline must be examined for fouling and foreign
1.4 Installation in the pipeline - Assembly
bodies prior to installation and cleaned if necessary.
Danger of injury!!
The applicable safety regulations in accordance with VGB 9a
must be adhered to.
The necessary personal safety equipment/clothing must be used.
Attention!
Note the direction of flow as indicated by the cast-on arrow on the
hous-ing and the arrow on the name plate!
The name plate is always fitted to the exit flange/exit side.
Figure 3
Figure 4 Flow direction Cast inscription
The counter flanges on the pipeline must be plan-parallel and concentric.
The connecting bolts must be tightened uniformly (avoiding distortion) and in crosswise alter-nating order. The pipeline must under no circumstances be pulled toward the valve to close the joint.
There should be sufficient space between the pipe flanges during installation of the valve, in order to avoid damage to the flanges and in order that gaskets can be installed.
Installation immediately downstream bends, T-joints or dampers and/or control valves should be avoided wherever possible.
Any unusual installation situations should be discussed and agreed with NOREVA.
Figure 5
Figure 6 Figure 7
Flow direction
Pump Noreva non return valve
Noreva non-return valve
Inspection and servicing/maintenance work may be performed only once the section of pipe in which the valve is installed has been isolated, depressurized and secured against reactivation.
Danger
DANGER
In case of escape of hazardous liquids, substances, gases and fumes/vapors, shut the system down im-mediately, inform the responsible supervisor and perform the corresponding repair work.
Personal safety equipment and clothing in accor-dance with the regulations issued by the profes-sional associations must be used.
There is a danger, depending on the medium con-ducted, of poisoning, corrosive burns, scalding, and also dangers arising from biological and microbi-ological substances and from fire and potential ex-plosion.
Caution
CAUTION
All pressure-conducting lines must be de-pressurized and secured against reactiva-tion before starting any servicing / main-tenance work.
All joints and connections must be checked for tightness and firm seating when the servicing /maintenance work has been completed.
NOREVA non-return valves require no servicing or maintenance.
2.1 Servicing and maintenance
The following checks within the scope of the standard servicing and maintenance intervals for the overall system are nonetheless recommended:
• Check of external leakage • Check for damage
• Check for fouling/freedom of movement • Check of unusual noises
The valve serial number should always be stated when ordering spare parts. This serial number can be found on the name plate (Figure 4) and on the valve flange.
2.2 Spare parts
The valves must be removed from the pipeline after depressurization of the line in order to replace parts.
2.3 Replacement of spare parts
Repair work on NOREVA non-return valves may be performed only by NOREVA or by per-sons trained and approved by NOREVA.
In case of malfunctioning of a valve, remove the valve from the pipeline and firstly inspect the seat (2) and valve disk (3) for damage, and remove any foreign bodies found.
IMPORTANT: DANGER OF CRUSHING!!
If this does not eliminate the problem, the nozzle/guide (5) must be pulled or pushed out of its seating in the direction of flow.
Any grub screws used to secure the nozzle/guide must be removed prior to dismantling. Any damage present can then be ascertained and parts replaced if necessary.
A new valve disk (3) must be ground against the seat (2) using a device (specific Noreva tool) and grinding paste during installation.
The nozzle (5) should first be positioned on its rib and the spring (4) and valve disk (3) then installed; then slip the housing (1) over the nozzle (5) and press or beat the collar of the nozzle into the housing seating using a suitable plate.
2.3.2 Assembly of non return valve NRV-Z / ZK / ZSK / K (Figure 8/8.1)
If the nozzle/guide was secured using grub screws, new threaded holes must be made and new grub screws installed. The grub screws should be secured using hardening adhesive (e.g. DELO 5298).
Valve functioning has now been restored, and the valve can be re-installed.
Our specialist technicians will be glad to assist with advice. Repairs can also be performed at short notice at our works.
Figure 8.1 Figure 8 Flow direction closed open Grub screw Flow direction open closed
2.3.3 Disassembly of non retrun valve NRV-B / BK (Figure 9)
In case of malfunctioning of a valve, remove the valve from the pipeline and firstly inspect the seat (2) and valve disk (4) for damage, and remove any foreign bodies found.
IMPORTANT: DANGER OF CRUSHING!!
If the above does not solve the problem, firstly remove the central bolt (8). Then lift out the nozzle ring (3) using the holes provided for this purpose. It must be ensured that the valve disk (4), which is not fixed to the nozzle ring (3) but instead only guided by the guide me-chanisms (6) remains in the housing (1).
Any damage present can then be ascertained and parts replaced if necessary. Ensure cor-rect location of the springs (5) between the guide mechanisms (6) and the nozzle ring (3). A new valve disk (3) must be ground against the seat (2) using a device and grinding paste during installation.
2.3.4 Assembly of non return valve NRV-B / BK (Figure 9)
The guide mechanisms must engage uniformly in the disk collar when the nozzle ring (3) is positioned on the valve disk (4). Tie the valve disk (4) and nozzle ring (3) together using not less than two plastic tapes and insert them into the housing (1). Then remove the tapes and screw in the central bolt (8). The central bolt must be secured using hardening adhe-sive (DELO 5298).
Tightening torque for central bolts out of material 42CrMo4V:
M24 = 350 Nm M36 = 1150 Nm M52 = 3500 Nm M72x6 = 10100 Nm M27 = 500 Nm M45 = 2250 Nm M56 = 4350 Nm M30 = 650 Nm M48 = 2700 Nm M64 = 6456 Nm Figure 9 Flow direction open closed
Our specialist technicians will be glad to assist with advice. Repairs can also be performed at short notice at our works.
2.4 Incident during operation / Corrective action
Problem Possible cause Correction
Leakage at the valve seat Depositions/fouling on the seat
Clean valve seat and disk. Note Section 2.
NRV incorrectly installed Pump delivering against closed non-return valve .
Install non-return valve in accordance with Section 1.4
