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Why Are Many Customers Surprised When They Receive DERVOS Valves?
Why Are Many Customers Surprised When They Receive DERVOS Valves?
2025-12-18

In the export of industrial valves, packaging is often regarded as merely the final step before delivery. However, during actual transportation, packaging directly affects the overall condition of the valve during transit, handling, and even at the moment the customer unpacks it.   For industrial valves that must undergo long-distance transportation and multiple transshipments, packaging itself is an integral part of product quality. Based on extensive export experience, DERVOS has established a clear, stable, and repeatable valve packaging standard to ensure that valves are delivered to customers safely and in perfect condition.   1. Pre-Packaging Preparation and Product Verification   Before entering the packaging process, all valves undergo cleaning, inspection, and product information verification. This stage ensures that each valve is in a stable and fully controlled condition before packaging.   ● Remove oil and grease from the valve body surface ● Inspect flange sealing surfaces and the valve cavity to ensure no foreign matter is present ● Install and securely fix the nameplate to ensure product information is clear and identifiable   This process provides a reliable foundation for subsequent protection and transportation.   2. Internal Anti-Corrosion Treatment and Sealing Surface Protection   To address the conditions typically encountered during export transportation, valves receive targeted protective treatment prior to packaging:   ● The valve cavity is evenly coated with anti-rust oil to reduce the risk of corrosion in humid or salt-laden environments ● Protective covers are installed on all flange faces to prevent impact damage or contamination during handling and transport   These measures ensure that both internal components and sealing surfaces remain in good condition until the valves arrive at the customer's site.   3. Multi-Layer Inner Packaging and Individual Valve Protection   During the inner packaging stage, DERVOS applies a multi-layer cushioning structure to provide comprehensive protection for each valve:   ● Impact-resistant pearl cotton is placed around all sides and at the bottom of the inner carton ● Separators are installed between valves to prevent direct contact ● Each valve is individually wrapped with protective cushioning material, with special attention given to coatings and machined surfaces   This packaging structure effectively reduces the risk of paint damage, abrasion, and surface defects during transportation.   4. Custom Partition Fixing and User-Friendly Design   When multiple valves are packed in the same crate, custom wooden partitions are used to secure each unit:   ● Valves are precisely positioned according to their dimensions to prevent movement inside the crate ● Partitions feature chamfered edges, making it easier for customers to open the crate and remove the valves ●&nb...

What are the differences between globe valves and gate valves?
What are the differences between globe valves and gate valves?
2025-12-12

In industrial piping systems, globe valves and gate valves are two of the most commonly used shutdown valves. Although both are designed for starting and stopping fluid flow, they differ significantly in structural design, operating principles, application scenarios, and overall performance. Understanding these differences helps engineers make informed selections that ensure system efficiency, reliability, and cost-effectiveness.   I. Key Differences in Structure and Operating Principles   1. Different opening and closing mechanisms Globe Valve: The disc moves up and down along a path perpendicular to the flow direction. Shutoff is achieved when the disc and seat sealing surfaces come into full contact. Gate Valve: The gate moves vertically in a manner similar to a “gate” that is either fully open or fully closed, with sealing achieved through surface compression.  This means that globe valves are suitable for precise throttling, while gate valves are mainly used for full open or full shut service.   2. Flow path design differences A globe valve has an S-shaped flow path that forces the medium to change direction, resulting in higher flow resistance. A gate valve features a straight-through flow path with minimal resistance and low pressure drop, making it better suited for long-distance transmission.   II. Differences in Application Scenarios   1. Throttling vs. On/Off Service Globe valves can be used for throttling and flow regulation, making them suitable for applications requiring high sealing performance and precise flow control, such as steam, cooling water, and various process media.   Gate valves are not suitable for throttling, as operating them in a partially open position may cause gate vibration, damage to the sealing surfaces, and fluid-induced impact. Gate valves are ideal for large-diameter pipelines where low flow resistance is required and switching frequency is relatively low, including oil transportation, water supply and drainage, and power plant systems.   2. Size range and installation space Globe valves are generally used in small to medium sizes (more common below DN50). Their body structure is heavier and requires more installation space. Gate valves are suitable for medium to large sizes. Due to their simpler design, they offer a cost advantage in larger dimensions.   III. Sealing Performance and Pressure Ratings   1. Differences in sealing surface design The globe valve features a tapered sealing surface, which achieves tight shutoff through axial compression, making it easier to obtain reliable sealing performance. The gate valve uses either parallel or wedge-type sealing surfaces. Its sealing effectiveness depends largely on the pressure applied by the gate and is more influenced by the system’s medium pressure.   2. Pressure and temperature adaptability Both valve types are suitable for medium- to high-pressure and high-temperature applications....

Key International Standards for Butterfly Valves: Detailed Overview of API 609, ISO 5752, and JB/T 8527
Key International Standards for Butterfly Valves: Detailed Overview of API 609, ISO 5752, and JB/T 8527
2025-12-05

Butterfly valves are widely used in industrial piping systems due to their compact structure, lightweight design, and quick operation. They are commonly applied in water treatment, chemical, power, oil, and gas industries. However, when dealing with industrial standards across different countries and regions, selecting a butterfly valve that meets the relevant specifications is crucial. This article provides a detailed analysis of butterfly valve design and selection requirements based on three key standards: API 609, ISO 5752, and GB/T 12238.   1. API 609 — American Petroleum Institute Standard   API 609 is the American Petroleum Institute (API) standard for metal-seated butterfly valves, primarily used in the oil, gas, and chemical industries. The standard defines valve structure, materials, dimensions, and pressure ratings to ensure reliable performance under high temperature, high pressure, and corrosive media conditions.   Key points include: ● Pressure Ratings: Covers Class 150 to 1500, accommodating various service conditions. ● Body and Disc Design: Metal-to-metal sealing requires precise alignment between disc and seat to prevent leakage under high temperature or high pressure. ● Testing and Inspection: Includes shell tests, seat leakage tests, and operational performance checks to ensure valve safety and reliability.   For high-temperature steam or high-pressure oil and gas pipelines, selecting a butterfly valve compliant with API 609 can significantly reduce leakage risk and extend equipment lifespan.   2. ISO 5752 — International Standard Organization Standard   ISO 5752 is the International Organization for Standardization (ISO) standard that specifies end dimensions and flange connection sizes for valves. It defines the face-to-face dimensions, flange sizes, and connection methods for butterfly valves, providing a consistent interface specification for industrial users worldwide.   Key points include: ● Face-to-Face Dimensions: Specifies valve lengths for different nominal diameters to ensure compatibility with piping systems. ● Flange Dimensions: Ensures valves match international standard pipe fittings, such as ANSI or DIN flanges. ● Interchangeability: Butterfly valves designed according to ISO 5752 can be replaced or serviced globally without redesigning the pipeline interface.   ISO 5752 is particularly suitable for multinational engineering projects, ensuring the universality of butterfly valves across different plants and systems.   3. JB/T8527 — Chinese National Standard   JB/T8527 is the Chinese national standard specifying the dimensions, structure, and testing requirements for metal hard-seal butterfly valves. It is widely applied in domestic industrial projects such as water conservancy, power, and petrochemical industries, serving as an important reference for procurement and acceptance.   Key ...

Line Blind Valve
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1" - 60" Class 150 - 2500 Line Blind Valve ASME B16.34

Line blinds are utilized in pipeline systems when there is a need for either complete closure or unimpeded flow transition without a significant drop in pressure. The THD (Through-Hole Design) enables swift and seamless adjustments in position. The THD-slide variant boasts a multi-bolt configuration, making it easier to operate with reduced face-to-face dimensions. The inclusion of extra body bolts renders this style particularly well-suited for high-pressure applications.

  • Payment:

    30% when order confirmed, 70% before shipment
  • Product Origin:

    China
  • Color:

    Customization
  • Shipping Port:

    Shanghai, China
  • Lead Time:

    30~60 days Ex Works after order confirmation
Inquiry now
Product Detail

Features

1. Swift Transition: Blinding can be performed safely in a matter of minutes, even by operators with minimal experience.

2. Economical Solution: Decreases maintenance hours, resulting in savings on labor costs.

3. Toolless Handling: The process is simplified with a hand-wheel operation, eliminating the need for tools to achieve full shut-off.

Standard Specifications

Size

1'' - 60'' (DN 25 to DN 1500)

Pressure Class

Class 150 - 2500 (PN 2.5 to PN 400)

Design & Manufacture code

ASME B16.34

Flange Standard

ASME B16.5

Material

Carbon Steel, Stainless Steel, Hastelloy, and Titanium

Actuation

Manual, Pneumatic Hydraulic and Electric

Technical Drawing

Adaptable Design

In addition to its conventional design, the THD-Slide is available in variations tailored for High-Temperature, Fire Safety, and Non-Drip applications. For installations constrained by limited space, a compact version can be provided as well.

Easy Seal Inspection

In this design, the seals are housed within the spectacle plate. This characteristic offers the advantage of convenient access for inspection and seal replacement. Assessing the condition of these seals can be performed external to the operational process, prior to any position changes, thereby ensuring the integrity of the seal's quality.

Cost Effectiveness

The THD-Slide features a straightforward and robust design engineered to deliver complete shutdown, extended operational lifespan, and cost-effective service with minimal maintenance requirements. The distinctive mechanism for opening and closing the THD-Slide enables a single individual to rapidly and safely blind pipelines without the need for any tools or equipment.

THD-Slide Cutout

Part Description

Part Description

Material

Handwheel

QT400-18

Stem

A182 F6A

Stem Nut

Alloy Copper

Body

A350 LF2

Seal Carrier

A350 LF2

Seals in plate

Viton

Spectade Plate

A350 LF2+ENP

Position Stop

A193 B7

Driving module

A350 LF2

Body stud/Nuts

A193 B7/A194 2H

Other materials and seal rings are available upon request

Options

●Hand Wheel Extensions

●Locking Device

●Limit Switches

●Drain/Vent ports

●Spectacle Plate Covers to Protect Seals

●Compact Design (integral tapped end flange)

●Rain/Dust Shield

●Torque Limiter

Operation of Standard

Mechanism Principle

In normal conditions, the blind valve's diversion hole is in contact with the pipeline, and the blind valve is in the open position. When maintenance is required, and the pipeline must be cut off, then loosen the stem of blind valve to move the flat end onto the pipeline, and make the blind valve turn to closed position from open position; tighten the stem and let the blind valve to perform sealing function and cut off the pipeline.

When the maintenance work is completed, loosen the stem and move the blind plate to the diversion hole and connected to the pipeline. The blind valve was turned to closed position from open one. Lock the stem, and seal it, the pipeline is now open, and the blind plate valve returns to the open position.

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Leave a message

    If you are interested in our products and want to know more details,please leave a message here,we will reply you as soon as we can.

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