DCV4 Stainless Steel Wafer-Type Disc Check Valve Installation and Maintenance Instructions

1. Safety Information

Safe operation can only be guaranteed if the product is properly installed, commissioned, operated and maintained by qualified personnel in accordance with these Installation and Maintenance Instructions (see Section 1.11). General installation and safety requirements for pipeline and plant construction must also be observed, and tools and safety equipment must be used correctly.

1.1 Intended Use

Refer to these Installation and Maintenance Instructions, the product nameplate and the Technical Information Sheet to confirm that the product is suitable for the intended use/application.

The following products comply with the requirements of the European Pressure Equipment Directive 2014/68/EU and are CE marked where required.

This product falls within the following EU Pressure Equipment Directive/UK Pressure Equipment (Safety) Regulations categories:

This product has been specifically designed for use with steam, compressed air, water and other industrial fluids within Group 2 of the above EU Pressure Equipment Directive/UK Pressure Equipment (Safety) Regulations.

ii) Check material suitability and the pressure and temperature limits, including their maximum and minimum values. If the maximum operating limits of the product are lower than those of the system in which it is installed, or if product failure could result in a dangerous overpressure or overtemperature condition, ensure that the system includes a safety device to prevent such limits from being exceeded.

iii) Determine the correct installation position and direction of fluid flow.

iv) Spirax Sarco products are not designed to withstand external stresses that may be imposed by the system in which they are installed. The installer is responsible for considering these stresses and taking adequate precautions to minimise them.

v) Before installation in steam or other high-temperature applications, remove all protective covers from connections and all protective film from nameplates, where applicable.

vi) Before use, the user must ensure that the fluid is compatible with the equipment materials.

1.2 Access

Ensure safe access before carrying out work on the product and, if necessary, provide a suitably protected safe working platform. If lifting is required, arrange suitable lifting equipment.

1.3 Lighting

Ensure adequate lighting, particularly where detailed or complex work is required.

1.4 Hazardous Liquids or Gases in the Pipeline

Consider what substances may be or may have been present in the pipeline: flammable substances, substances hazardous to health, and extreme temperatures.

1.5 Hazardous Environment Around the Product

Consider: explosion-hazard areas, oxygen-deficient atmospheres (such as tanks and pits), hazardous gases, extreme temperatures, hot surfaces, fire hazards (such as during welding), excessive noise and operating machinery.

1.6 The System

Consider the effect of the proposed work on the entire system. Could any proposed action, such as closing isolation valves or electrical isolation, put another part of the system or personnel at risk? Hazards may include isolating vents or protective devices, or rendering controls or alarms ineffective. Ensure that isolation valves are opened and closed progressively to avoid system shock.

1.7 Pressure Systems

Ensure that pressure is isolated and safely vented to atmospheric pressure. Consider double isolation (double block and bleed), and locking or tagging closed valves. Do not assume that the system has been depressurised even when a pressure gauge indicates zero.

1.8 Temperature

Allow time after isolation for the temperature to return to normal to avoid the risk of burns, and consider whether protective clothing, including safety glasses, is required.

Viton Seats:

If a Viton seat has been subjected to temperatures close to 315 °C (599 °F) or higher, it may have decomposed and formed hydrofluoric acid. Skin contact and inhalation of any fumes must be avoided, as this acid can cause deep skin burns and damage the respiratory system.

1.9 Tools and Consumables

Before starting work, ensure that suitable tools and/or consumables are available. Use only genuine Spirax Sarco spare parts.

1.10 Protective Clothing

Consider whether you and/or others nearby require protective clothing to guard against hazards such as chemicals, high/low temperatures, radiation, noise, falling objects, and risks to the eyes and face.

1.11 Permit to Work

All work must be carried out or supervised by suitably competent personnel.

Installation and operating personnel must be trained in the correct use of the product in accordance with these Installation and Maintenance Instructions.

Where a formal “permit to work” system is in force, it must be followed. Where no such system exists, it is recommended that a responsible person is aware of the work being carried out and, where necessary, arranges for an assistant whose primary responsibility is safety.

Display “warning notices” where necessary.

1.12 Handling

Manual handling of large and/or heavy products may present a risk of injury. Lifting, pushing, pulling, carrying or supporting a load by physical effort may cause injury, particularly to the back. It is recommended that the risks are assessed by considering the task, the individual, the load and the working environment, and that an appropriate handling method is used according to the circumstances.

1.13 Residual Hazards

Under normal operating conditions, the external surface of the product may be very hot. When used at the maximum permitted operating conditions, the surface temperature of some products may reach 400 °C (752 °F).

Many products are not self-draining. Take particular care when dismantling or removing the product from its installation position (see “Maintenance Instructions”).

1.14 Frost Protection

Measures must be taken to protect products that are not self-draining from frost damage where they may be exposed to temperatures below freezing point.

1.15 Disposal

Unless otherwise stated in these Installation and Maintenance Instructions, this product is recyclable and, provided due care is taken, no ecological hazard is anticipated with its disposal. However, if the valve is fitted with Viton or PTFE seats, special care must be taken to avoid health hazards that may result from the decomposition/burning of these seats.

Viton:

• Can be disposed of by landfill in accordance with national and local regulations.

• Can be incinerated, but a scrubber must be used to remove hydrogen fluoride produced by product decomposition, in accordance with national and local regulations.

• Insoluble in aqueous media.

Obtain the latest information on any substances of concern that may be contained in this product. Unless additional information is provided on the Spirax Sarco Product Compliance webpage, this product can be safely recycled and/or disposed of provided it is handled with care. Always comply with local recycling and disposal regulations.

1.16 Product Return

Customers and distributors are reminded that, under EU health, safety and environmental legislation, when returning products to Spirax Sarco they must provide information on any hazards and the precautions to be taken due to contamination residues or mechanical damage that may present a health, safety or environmental risk. This information must be provided in writing, including health and safety data sheets relating to any substances identified as hazardous or potentially hazardous.

2. Product Information

2.1 Description

The DCV4 stainless steel disc check valve is of wafer construction, designed for installation between ASME flanges. It is suitable for a wide range of fluid applications, including process lines, hot water systems, steam and condensate systems. The face-to-face dimension complies with EN 558 Part 2, Series 52.

Standard valves are fitted with metal-to-metal seats for steam applications. Alternative seat materials are available for oil, air, gas and water applications - see Section 2.5.

Standards

This product fully complies with the requirements of the European Pressure Equipment Directive 2014/68/EU.

Standard Shut-off

Standard valves comply with EN 12266-1 Class E.

Valves complying with EN 12266-1 Class D are available on request.

Soft-seat versions comply with EN 12266-1 Class A when subject to a differential pressure.

Certification

This product is available with certification to EN 10204 3.1.

Note: All certification/inspection requirements must be specified at the time of ordering.

Note: For further product information, see Technical Information Sheet TI-P144-01-EN-ISS1.

2.2 Sizes and Pipe Connections

DN15, DN20, DN25, DN40, DN50, DN80 and DN100.

Suitable for installation between ASME 150 or ASME 300 flanges.

2.3 Options

High-temperature spring for temperatures up to 400 °C (752 °F).

Viton soft seat for oil and gas applications.

EPDM soft seat for water applications.

Figure 1

2.4 Materials

2.5 Seat Options

The valve is stamped to identify the internal components fitted:

2.6 Pressure/Temperature Limits

This product must not be used in this region.

A-B-D High-temperature spring and no spring.
E-C-D Standard spring.
Please note: The data shown are valid only when metal-to-metal seats are used. If Viton or EPDM seats are used, the product is limited by the selected seat material.

2.7 Body Marking Information

Figure 2

Rolled body markings and description

3. Installation

Note: Before carrying out any installation work, observe Section 1, “Safety Information”.

Refer to these installation and maintenance instructions, the product nameplate and the technical information sheet to confirm that the product is suitable for the intended installation conditions:

3.1 Check the materials, pressure, temperature and their maximum values. If the maximum operating limits of the product are lower than those of the system in which it is installed, ensure that a safety device is fitted to the system to prevent overpressure.

3.2 Determine the correct installation position and fluid flow direction.

3.3 Before installation in steam or other high-temperature applications, remove all protective covers from connections and all protective films from nameplates, where applicable.

3.4 The valve may only be installed with “weld neck” flanges. Other flange types may restrict valve operation.

3.5 The disc check valve is installed directly between two pipe flanges (see Figure 3). Use standard gaskets on both sides of the valve together with longer bolts or stud bolts.

Note: Flanges, bolts (or stud bolts), nuts and joint gaskets are supplied by the installer. Normal and appropriate flange bolt tightening procedures should be followed, such as tightening bolts diagonally in an opposing sequence.

3.6 DCV4 can be installed between ASME 150 or 300 flanges. Except for DCV units without an internal spring, they may be installed in any orientation; versions without a spring must be installed in vertical pipework with flow from bottom to top (i.e. upward flow, see Figure 3b). The disc check valve must be installed in accordance with the flow direction arrow on the valve body, which indicates the correct fluid flow direction.

Note: Disc check valves are not suitable for applications with severe pulsating flow, such as locations near compressors.

‘b’ is the only acceptable installation orientation for DCV units without an internal spring

Figure 3

4. Commissioning

After installation or maintenance, ensure that the system is fully operational. Test any alarms or protective devices.

5. Operating Principle

The disc check valve is opened by fluid pressure and closed by the spring after flow stops and before backflow occurs.

Figure 4

Kv Values

Conversion formulas:
Cv (UK) = Kv x 0.963
Cv (US) = Kv x 1.156

Opening Pressure (mbar)

Differential pressure at zero flow for the standard and high-temperature springs.

Flow direction

For minimum opening pressure, a springless valve can be installed in a vertical pipeline with the flow direction upwards.

6. Maintenance

Note: Before carrying out any maintenance work, observe the requirements in Section 1, “Safety Information”.

This product is maintenance-free.

Note: If a DCV is dismantled with the heavy-duty spring fitted, take particular care because the spring force may cause the retainer to be ejected from the valve body.

7. Spare Parts

No spare parts are available for this product.

How to Order a New Product

Example:

1 x Spirax Sarco DN25 DCV4 stainless steel disc check valve for installation between ASME 150 flanges.