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LESER Change-over Valves

LESER Change-over Valves
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LESER Change-over Valves

Product catalog summary
Overview
LESER Change-over Valves, specifically Types 330 and 320, are designed to ensure high plant availability by allowing uninterrupted operation and minimizing safety risks during maintenance. These valves are crucial in industries such as petrochemical, oil and gas, technical gases, chemicals, and refrigeration.
Applications and Advantages
Change-over valves connect two safety valves to a pressure system, enhancing operational availability. One valve remains operational while the other is on standby, allowing for maintenance without system shutdown. Key advantages include flow-optimized design for minimal pressure loss, robust maintenance-free construction, and fast availability with synchronized delivery times.
Design Features
Both valve types are available in various configurations, including single change-over and lockable combinations. They support a range of valve sizes (DN 25 – DN 400 / NPS 1" – 16") and pressure ratings (Type 330: PN 10 – PN 40 / CL150 – CL300; Type 320: PN 10 – PN 250 / CL150 – CL1500). Materials include steel, low-temperature steel, and stainless steel, with options for customization.
Pressure Loss and Calculation
Pressure loss in the inlet line should not exceed 3% of the set pressure to ensure stable valve function. The design of the change-over valve, including flow geometry and area, is optimized to minimize pressure loss. The pressure loss coefficient (zeta value) is crucial for calculations, with lower values indicating less pressure loss.
Ordering and Customization
To order, specify the base construction, operating conditions, materials, design regulations, and connection details. Options for customization include seals for tightness requirements and NACE compliance.
Approvals
LESER Change-over Valves comply with international standards, including the Pressure Equipment Directive (PED 2014/68/EU) and ASME B16.34, ensuring global usability.
Specifications
The document provides detailed specifications for change-over valves and safety valves, including dimensions, pressure ratings, and materials. The valves are available in various nominal pipe sizes (NPS) ranging from 1" to 16" and pressure ratings according to DIN EN 1092 and ASME B16.5 standards.
Pressure Loss Coefficient and Flow Coefficient
The pressure loss coefficient (zeta) and flow coefficient (CV) for different NPS sizes are provided. For example, a NPS 1" valve has a zeta of 0.19 and a CV of 66 US-GPM.
Dimensions and Weights
Dimensions such as E1, C2, and s are specified in inches, with weights provided in pounds. For instance, a NPS 1" valve has an E1 dimension of 14 15/16 inches and weighs 326 lbs.
Materials and Temperature Limits
The document outlines materials used for different pressure ratings and temperature limits. For example, WCB material is used for certain valves with a pressure rating of CL1500 and a temperature limit of up to 752°F.
Flange Drillings and Facings
Flange drillings and facings comply with DIN EN 1092 and ASME B16.5 standards. Various flange facings are available, such as raised face and ring joint face.
Lockable Combinations
Lockable combinations are described for use with safety valves, ensuring synchronized operation and preventing improper use. These combinations are used in applications where media cannot be discharged into the atmosphere.
Applications
The lockable combination is suitable for valuable or hazardous media, connecting safety valves to a joint blow-off line while isolating one valve.
Options and Expansions
Options for increasing nominal sizes and using NACE-compliant materials for sour gas applications are available. Drain holes are provided for steam protection and condensate discharge.
Material and Cleaning Options
The document outlines options for higher quality spindle materials and pickled versions for stainless steel configurations. Cleaning standards are specified for oil and grease-free requirements, particularly for technical gases and oxygen applications.
Connection and Pressure Relief Options
Various connection options are available, including remote sensing, purge and manometer connections, and pressure relief with needle valves. These are designed to facilitate safe maintenance and operation under different pressure conditions.
Switching and Safety Features
Proximity switches and adjustment guards are available to prevent unauthorized switching and indicate the active safety valve. A pressure balancing unit is recommended for high-pressure applications to prevent damage during switch-over.
Global Presence
LESER operates globally with subsidiaries and representatives in over 80 countries, emphasizing its focus on safety valves and market leadership.
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Catalog excerpts

LESER Change-over Valves-1

Best Availability LESER Change-over Valves Type 330, Type 320

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LESER Change-over Valves-2

High operating to set pressure ratio, high backpressure or low total height? High Efficiency Clean Service application? Clean Service Critical Service Valve finder Your path to the right product group Critical Service / highly corrosive application? Steam, gas and liquid application with low capacity in relation to valve size? Modulate Action Spring loaded Safety Relief Valves High Performance Required Orifice letter? Best Availability Bursting disc High plant availability important? Changeover valves Compact Performanc

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LESER Change-over Valves-3

Contents Type 330, Type 320 Page LESER Type General information Valve finder LESER Change-over Valves Applications, industries, advantages Article numbers and technical data Metric units US units Basics Design and pressure loss coefficient Calculation pressure loss Type 330 Compact, Type 320 Flow Designs, materials LESER Type Type 330 Compact Article numbers and technical data Metric units US units Flange facings, Temperature limits Lockable combination Dimensions - Metric units - US units LESER worldwide

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LESER Change-over Valves-4

LESER Change-over Valves Applications Change-over valves are used in various industries in order to ■ ensure uninterrupted operation ■ minimise safety risks due to unplanned shutdown periods. These industries are ■ Petrochemical industry ■ Oil and gas industry ■ Technical gasses ■ Chemicals industry ■ Refrigeration Safety valve side Piping side Change-over valves are used to connect two safety valves with a pipe connection to a pressure system, in order to increase operational availability. One safety valve is in operation and one safety valve is on standby. The standby safety valve can be disassembled...

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LESER Change-over Valves-5

General information Type 330, Type 320 Two change-over valve types Design features Type 330 Compact offers the solution for low-pressure loss requirements Valve sizes DN 25 – DN 400 / NPS 1" – 16" Pressure ratings Type 330 Compact: PN 10 – PN 40 / CL150 – CL300 Type 320 Flow: PN 10 – PN 250 / CL150 – CL1500 Flange drillings in accordance with DIN EN 1092 and ASME B16.5 Body materials Type 330 / 320 Type 320 Flow has an optimal flow path for highest pressure loss requirements Low-temperature steel Stainless steel Other materials for special requirements available upon request. Options Change-over...

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LESER Change-over Valves-6

Basics Design and pressure loss coefficient Basics Pressure loss in the inlet line is considered to be the pressure difference between the pressure in the system to be safeguarded and the pressure in front of the safety valve during discharge. When a safety valve is activated, the flow losses in the inlet line cause a pressure loss. The pressure loss in the inlet line may not exceed 3% of the set pressure in accordance with applying international standards. If the 3% limit is exceeded, the safety valve may not show a stable function any longer (chatter). As a consequence, the full power may not...

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LESER Change-over Valves-7

Basics Calculation of pressure loss To calculate the pressure loss in the inlet line to the safety valve entrance, the change-over valve as well as possible addition piping sections and installations must be considered. To do so, the inlet pipe system is divided into sections. A section is formed for each flow or reference diameter. In the following example, two sections can be formed. One for the change-over valve (∆pwv) and one for the connected piping (∆p1). Piping – all piping sections – separate pressure loss calculation for different flow diameters – reducers for connecting pipes of different...

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LESER Change-over Valves-8

Designs Type 330, Type 320 Type 330 Compact The change-over valve Type 330 Compact is flow-optimized and at the same time compact for installation. It is the best solution if the requirements of the combined safety valves or the additional piping of the pressure loss are not unusually high. Due to its compact design, it is cost-efficient so that it represents the most economical solution for a safety valve/change-over valve combination. In lockable combinations, it can be selected as standard at the outlet since there are no increased requirements of the pressure loss via the change-over valve...

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LESER Change-over Valves-9

How to Order Type 330, Type 320 Composition of the article number 3300.0010 0: Global Configuration 001: Counting number (nominal size, pressure rating) 0: C onfigurable base material - Q09: Steel, body material 1.0619 / WCB - Q10: Low-temperature steel, body material LCB - Q11: Stainless steel, body material 1.4408 / CF8M 330: Type Order specification In order to clearly specify a change-over valve, the following information is required: Base construction Article number Operating temperature Operating pressure [barg / psig ...] Body materials Design regulations Other materials Connections Safety...

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LESER Change-over Valves-10

Designs Type 330, Type 320

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LESER Change-over Valves-11

Materials Type 330, Type 320 Item Inlet body Elbows – Activation side Depending on pressure and size: Depending on pressure and size: Option Code Packing gland Position indicating device Hand wheel Graphite Graphite Graphite Graphite Graphite Graphite Type 320 DN 80/3" and DN 100 / 4" in PN 250/CL1500: – PED: 1.4980 / Gr. 660B – ASME: Gr. 660B – PED / ASME: 1.4980 / Gr. 660B 2) For some article numbers LESER reserves the right to use higher quality materials at higher temperatures. 3) Type 330 DN 200 to DN 300, Type 320 DN 125 to DN 200: – Studs: A4-70 / B8M – Nuts: A4-70 / 8M 1) Please note...

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LESER Change-over Valves-12

Type 330 Compact Article numbers and technical data Metric units Safety valve side Pressure rating body basic construction Piping side Pressure loss coefficient (zeta) KVS (rt, water) Weight H dimension standard H dimension extended Weight H dimension extended Safety valve side Piping side Pressure loss coefficient (zeta) Weight H dimension standard Weight H dimension extended Expansion piping side Safety valve side Piping side Pressure loss coefficient (zeta) KVS (rt, water) Weight H dimension standard Weight H dimension extended The flange thickness and the outer diameter of the connection...

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*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.