Comprehensive Interpretation of Gate Valve Drawings

In industrial pipeline systems, gate valves serve as key equipment for controlling fluid on-off. Every link of their design, produksi, instalasi, and maintenance relies on accurate gate valve drawings for guidance. Gate valve drawings are not only the “communication language” for engineering and technical personnel but also the core basis for ensuring valve performance and system safety. Whether you are a novice new to the valve industry or an experienced technical expert, your ability to accurately interpret gate valve drawings directly affects work efficiency and project quality. This article will start with the basic composition of gate valve drawings, and gradually delve into key contents such as the interpretation of core components, application of technical standards, and scenario-based selection. Combined with practical cases of well-known enterprises like farpro valve, it will present you with a comprehensive and professional guide for interpreting gate valve drawings.

SAYA. Basic Understanding of Gate Valve Drawings: Grasp the “Framework” of Drawings

Gate valve drawings are engineering documents that integrate mechanical drawing specifications and valve industry standards. Their core function is to clearly convey the structural dimensions, pemilihan materi, technical requirements, and installation specifications of gate valves. Before approaching specific drawings, it is necessary to master their basic composition and general rules, which is the “stepping stone” for interpreting drawings.

1.1 Core Components of Gate Valve Drawings

According to industrial drawing standards and valve industry specifications, a complete set of gate valve drawings usually includes the following 6 core parts, which are interrelated and jointly form a complete technical information system:

• Title Block: Located at the lower right corner of the drawing, it serves as the “identity card” of the drawing. It includes the drawing name (MISALNYA., “Z41W-16P Stainless Steel Flanged Gate Valve”), drawing number (MISALNYA., “FP-ZG-2025-001”, where “FP” can stand for the abbreviation of farpro valve), skala (commonly 1:5, 1:10, dll.), design unit, design date, reviewer, and other information. The title block of farpro valve’s gate valve drawings also marks the product implementation standards, seperti API 600 or GB/T 12234 (National Standard of the People’s Republic of China for Steel Gate Valves), facilitating users to trace quality basis.
• View System: Gate valves have complex structures and need to be displayed through a combination of multiple views. The main view usually adopts a sectional view (MISALNYA., full section, half section) to clearly show the internal structures such as the valve body, gerbang, and valve stem; the side view is used to display the installation dimensions and external contour of the valve; the top view focuses on reflecting the flange connection dimensions or handwheel position. For gate valves with special structures (such as non-rising stem gate valves), local enlarged views are also added to mark details such as sealing surfaces and threads.
• Dimension Marking: It is divided into two categories: structural dimensions and installation dimensions. Structural dimensions include key parameters such as valve body wall thickness, gate thickness, and valve stem diameter, which directly affect the valve strength; installation dimensions cover flange diameter, number and spacing of bolt holes, total valve height, connection end distance, dll., and are the core basis for pipeline installation. Misalnya, for a DN100 PN40 gate valve, the drawing will clearly mark that the minimum wall thickness of the valve body is ≥6.4mm, and the valve stem diameter is ≥17.5mm (in accordance with the Q/TC 001-2022 standar).
• Material Marking: Material grades are marked with words or codes next to each component. Misalnya, the valve body is marked with “CF8” (304 besi tahan karat), the valve stem with “316”, and the seal with “PTFE + Graphite”. In the drawings of farpro valve’s stainless steel gate valves, it is specially noted that the materials comply with GB/T 12225 (National Standard of the People’s Republic of China for Copper Alloy Valves) or ASTM standards, ensuring that the corrosion resistance is compatible with the industrial environment.
• Technical Requirements: It centrally explains the performance indicators, processing accuracy, test requirements of the gate valve in text form, seperti “Shell test pressure is 1.5 times the nominal pressure, no leakage for 60 consecutive seconds”, “Sealing surface roughness Ra ≤ 3.2μm”, “Handwheel closes clockwise and opens counterclockwise”.
• Part List: It lists the serial number, name, quantity, and material of all component parts of the gate valve, such as valve body, gerbang, penutup katup, batang katup, roda tangan, sedang mengemas, dll.. It is an important reference for production procurement and assembly. In the drawing of Z41W gate valve of Shanghai Langu Valve, the part list can include 18 items of part information, covering all components from the main body to accessories.

1.2 Common Symbols and Specifications of Gate Valve Drawings

Gate valve drawings adopt common mechanical drawing symbols and integrate special identifiers of the valve industry. Mastering these symbols is the basis for quickly interpreting the drawings:

• Connection Method Symbols: Flange connection is represented by “○”, threaded connection by “∟”, and welded connection by “△”. These symbols are clearly marked at both ends of the valve in the drawing. Misalnya, in the drawing of farpro valve’s flanged gate valve, the flange is marked with the standard code “JB/T 79.1” (Mechanical Industry Standard of the People’s Republic of China for Raised Face Flanges), indicating that the flange dimensions comply with this specification.
• Sealing Surface Symbols: Soft seal is represented by “⊂⊃”, and hard seal by “□□”. Pada saat yang sama, the seal material code is marked (MISALNYA., “F” represents fluororubber). For gate valves with metal-to-metal seals, the drawing will indicate the surfacing material of the sealing surface, seperti “STL” (hard alloy).
• Tolerance and Fit Symbols: Key parts such as the fit between the valve stem and the valve stem nut, and the fit between the gate and the valve seat will be marked with tolerance grades, seperti “φ20H7/f6”, where “H7” is the hole tolerance and “f6” is the shaft tolerance, ensuring the flexibility and sealing of moving parts.
• Surface Roughness Symbols: Represented by “√” and numerical values. Misalnya, the valve body surface is marked with “√Ra6.3”, and the sealing surface with “√Ra3.2”. The smaller the value, the smoother the surface and the better the sealing performance.

Selain itu, gate valve drawings must comply with unified standards. Di dalam negeri, GB/T 12221 (Structural Lengths of Valves) and GB/T 1047 (Nominal Sizes for Pipes and Fittings) are commonly used. Secara internasional, API 600 (American Petroleum Institute Standard for Steel Gate Valves) and BS 1414 (British Standard for Valves) are adopted. As a global valve enterprise, farpro valve marks both national and international standards on its drawings to meet the needs of customers in different regions.

II. Interpretation of Core Component Drawings of Gate Valves: Correlative Analysis from Structure to Performance

The performance core of a gate valve depends on the design of key components such as the valve body, gerbang, and valve stem. The parameter markings of these components in the drawings directly determine the pressure resistance, kinerja penyegelan, and service life of the valve. The following will interpret the key points of each core component’s drawings in detail, combining specific drawing details and the product characteristics of farpro valve.

2.1 Badan Katup: Itu “Load-Bearing Framework” of the Gate Valve

The valve body is the main component of the gate valve, bearing the medium pressure and playing a role in installation and fixation. The core of its drawing markings is strength and connection parameters.

In the main view of the drawing, the valve body is usually presented in a sectional view, and the following 3 points need to be focused on:

• Wall Thickness and Material: The drawing will mark the wall thickness of each part of the valve body, especially the stress concentration areas such as the flange root and valve cavity bottom. According to the Q/TC 001-2022 standar, the minimum wall thickness of the DN100 PN40 gate valve body is ≥6.4mm. In the drawings of farpro valve’s stainless steel gate valves, an additional 0.5-1mm process allowance is added on this basis to improve the safety factor. In terms of material marking, “WCB” (baja karbon) is marked for general working conditions, Dan “CF8” (304 besi tahan karat) atau “CF8M” (316 besi tahan karat) for corrosive working conditions. Its stainless steel valve bodies all comply with the GB/T 12225 standard to ensure corrosion resistance.
• Flow Channel Dimensions: The drawing will mark the minimum diameter of the flow channel in the valve body. Misalnya, the minimum diameter of the flow channel of a DN100 gate valve is ≥75mm. The flow channel should be designed as a straight-through type to reduce fluid resistance. In the drawings of farpro valve’s gate valves, the inner wall of the flow channel is marked with a roughness requirement of “Ra ≤ 6.4μm” to reduce the erosion and wear caused by the medium.
• Connection Structure: For the valve body with flange connection, the drawing will mark parameters such as flange diameter (D), bolt hole center circle diameter (D1), number and diameter of bolt holes (n-φd). Misalnya, a DN100 PN16 flange is marked with “D=220mm, D1=180mm, n=8-φ18mm”. The matching degree with the pipeline flange directly affects the installation sealing performance.

The technical requirements of the valve body drawing will also clearly specify the water pressure test standard, seperti “Shell test pressure is 2.4MPa (1.5×PN16), no leakage for 60 seconds”. farpro valve inspects all valve bodies according to this standard before leaving the factory to ensure no sand holes, retak, or other defects.

2.2 Gate and Sealing System: Itu “Sealing Core” of the Gate Valve

The sealing system composed of the gate and the valve seat is the key for the gate valve to control the fluid. Its drawing design directly determines the sealing performance of the valve and is the top priority of interpretation.

Key points of gate marking in the drawing:

• Structural Form: The drawing will clearly indicate the type of gate. Misalnya, a wedge gate valve is marked with “wedge angle 5°”, which is suitable for high-pressure sealing; a parallel gate valve is marked with “double gate + spring”, which is suitable for low-pressure and large-diameter scenarios. In the drawing of farpro valve’s Z40W wedge gate valve, the guide structure dimensions of the gate are specially marked to reduce wear during opening and closing.
• Sealing Surface Parameters: The width, angle, and roughness of the sealing surface are core markings, seperti “sealing surface width 5mm, angle 30°, Ra ≤ 3.2μm”. For hard-sealed gate valves, the drawing will also mark the surfacing material, seperti “sealing surface surfacing with STL, thickness 2mm”, to improve wear resistance.
• Material Matching: The gate material must be compatible with the valve body and the medium. The drawing will mark “gate material is consistent with the valve body (CF8)” atau “gate material is 316L, valve body material is CF8” for strong corrosive medium scenarios.

The drawing marking of the valve seat usually corresponds to the gate, including the connection method between the valve seat and the valve body (such as threaded connection, pengelasan), sealing material (seperti “valve seat sealing surface is covered with PTFE”), and assembly requirements (seperti “interference fit between the valve seat and the valve body, fit tolerance H7/s6”). In the drawing of farpro valve’s sealing system, it is marked that “seal test pressure is 1.76MPa (1.1×PN16), leakage rate ≤ 8mm³/s (DN100)”, which complies with the GB/T 13927 standar (Valve Pressure Test).

2.3 Valve Stem and Drive System: Itu “Operation Center” of the Gate Valve

The valve stem connects the gate and the drive device and is the core component for transmitting operating force. The focus of its drawing marking is on strength and flexibility.

• Dimensions and Material: The drawing will mark the diameter, length, and thread parameters of the valve stem, seperti “valve stem diameter φ20mm, length 300mm, thread M20×2”. In terms of material, “20cr13” is marked for general working conditions, Dan “316” for corrosive working conditions. In the drawing of farpro valve’s valve stem, it is specially noted that “the valve stem surface is chrome-plated, with a coating thickness ≥ 0.05mm” to improve wear resistance and corrosion resistance.
• Fit and Accuracy: The fit between the valve stem and the stuffing box of the valve cover is marked with “φ20H7/f6” to ensure sealing performance; the thread fit between the valve stem and the valve stem nut is marked with “M20×2-6g” to ensure smooth opening and closing. The drawing also marks “valve stem straightness ≤ 0.1mm/m” to avoid jamming caused by bending.
• Drive Device Matching: Manual gate valves are marked with handwheel dimensions (MISALNYA., “handwheel diameter 200mm, material HT200”) and operating force (MISALNYA., “maximum operating force ≤ 360N”); electric gate valves are marked with actuator connection dimensions, torque requirements (MISALNYA., “actuator torque ≥ 500N·m”) and signal interface (MISALNYA., “4-20mA analog output”).

2.4 Packing and Valve Cover: Itu “Leak-Proof Barrier” of the Gate Valve

The valve cover and packing work together to prevent the medium from leaking from the valve stem. The focus of their drawing marking is on sealing reliability.

The valve cover drawing is marked with “valve cover wall thickness ≥ 6.4mm (consistent with the valve body), connected with the valve body by bolts, bolt specification M16×50, quantity 8”, and the sealing surface adopts “gasket sealing, gasket material 304 + graphite”. The stuffing box part is marked with “stuffing box depth 50mm, packing material PTFE + flexible graphite, packing layer number 4”, and clearly states that “the fit gap between the gland and the stuffing box ≤ 0.1mm”. In the drawing of farpro valve’s valve cover, it is marked with “torsion resistance test 465N·m (DN100), no damage for 10 seconds”, which meets the installation performance requirements.

AKU AKU AKU. Technical Requirements and Inspection Standards of Gate Valve Drawings: Itu “Red Line” for Ensuring Quality

The technical requirements part of the gate valve drawing is the core basis for valve production and inspection, covering various specifications such as materials, pengolahan, and testing, which must be strictly followed. The following will interpret the key contents of the technical requirements in combination with mainstream standards such as Q/TC 001-2022 and API 600.

3.1 Material Technical Requirements

The drawing will clearly specify the material standards and performance requirements of each component, seperti:

• Copper alloy castings comply with GB/T 12225, and forgings comply with GB/T 20078 (National Standard of the People’s Republic of China for Forged Steel Valves);
• The chromium content of stainless steel materials is ≥12% (in line with the definition of stainless steel), and the intergranular corrosion resistance test is qualified;
• For gate valves used in drinking water, the materials must comply with the GB/T 17219 hygiene standard (Hygienic Standard for Drinking Water Equipment and Protective Materials) without heavy metal precipitation.

In the drawings of farpro valve’s stainless steel gate valves, a material quality certificate number is additionally marked to ensure material traceability. The corrosion resistance of its stainless steel materials has been verified by a salt spray test, showing no rust for 500 hours.

3.2 Processing and Assembly Requirements

These requirements directly affect the accuracy and performance of the valve, and the core markings include:

• The valve body thread complies with GB/T 7307 (Cylindrical Pipe Threads) or GB/T 12716 (60° Seal Threads), and the thread axis angle deviation is ≤1°;
• When the gate is fully open, it must not stay in the valve body channel; when closed, the center line of the sealing surface is higher than the sealing surface of the valve body;
• After assembly, the valve opens and closes flexibly, with no jamming after 5 consecutive operations, and the handwheel opening and closing direction is clearly marked (closes clockwise, opens counterclockwise).

3.3 Testing and Inspection Standards

The drawing will clearly specify the items, methods, and qualification standards of factory inspection and type inspection, which are the final guarantee of valve quality. The common markings are shown in the following table:

Test Type	Sedang	Test Pressure	Duration	Qualification Criteria
Shell Test	Liquid	≥1.5 times the nominal pressure	DN≤50: 15s; DN65-100: 60s	No structural damage, no leakage
Seal Test	Liquid	≥1.1 times the nominal pressure	Same as above	Leakage rate ≤ 0.08×DN mm³/s
Gas Seal Test	Gas	0.6±0.1MPa	Same as above	No air bubbles overflow
Torsion Resistance Test	—	DN100: 465N·m	10s	No damage, passes shell/seal test

In the drawings of farpro valve’s gate valves, “type test triggering conditions” are additionally marked, including new product finalization, major material/process changes, and resumption of production after half a year of shutdown. The sampling rule is implemented according to “DN50-100: 3 units sampled from 20 units”, and full-item testing is conducted to ensure stable batch quality.

IV. Differences in Gate Valve Drawings Under Different Scenarios: Itu “Core Basis” for Selection

Gate valves are used in a variety of scenarios, from municipal water supply and drainage to industrial fields such as chemical industry, tenaga listrik, and petroleum. Different working conditions have significantly different performance requirements for gate valves, which are reflected in the drawings as targeted designs of parameters and structures. The following will interpret the differential key points of the drawings in combination with typical scenarios.

4.1 Water Supply and Drainage Scenario: Focus on Corrosion Resistance and Installation Convenience

In the municipal water supply and drainage system, gate valves need to withstand soil corrosion and scouring by impurities in water. The key points of drawing marking include:

• The valve body material is marked with “ductile iron QT450-10” atau “stainless steel CF8”, and the inner wall is marked with “epoxy resin coating, thickness ≥ 300μm” to prevent rust;
• The flow channel is marked with “straight-through type, diameter ≥ DN” to reduce sediment accumulation and avoid blockage;
• The installation dimension is marked with “non-rising stem structure, total height ≤ 600mm” to adapt to narrow spaces such as underground pipe galleries;
• The hygiene requirement is marked with “complies with GB/T 17219, drinking water safety certification”.

For the gate valve drawings of farpro valve designed for water supply and drainage scenarios, A “mud scraping groove” structure is specially designed, which is marked at the bottom of the gate to effectively remove sediment on the sealing surface and improve the service life.

4.2 Chemical Industry Scenario: Focus on Corrosion Resistance and Sealing Reliability

Chemical media are mostly acid-base corrosive fluids, with large fluctuations in pressure and temperature. The core of drawing marking is material corrosion resistance and sealing performance:

• The valve body and gate materials are marked with “316L stainless steel” atau “Hastelloy C276”, and it is noted that “resistant to 30% sulfuric acid, temperature ≤ 180℃”;
• The sealing surface is marked with “metal-to-metal hard seal, surfacing with Hastelloy” to avoid corrosion of the soft seal;
• The pressure is marked with “PN40, working temperature -20℃ ~ 180℃”, and the valve body wall thickness is designed according to the PN63 standard to reserve a safety margin;
• The middle cavity is marked with “additional pressure relief hole to prevent pressure increase caused by medium accumulation”.

4.3 High-Temperature and High-Pressure Scenario (MISALNYA., Electric Power, Petroleum): Emphasize Strength and High-Temperature Resistance

Under high-temperature and high-pressure scenarios, gate valves need to withstand extreme working conditions. The focus of drawing marking is strength and thermal stability:

• The valve body material is marked with “chrome-molybdenum steel WC9”, and the valve stem is marked with “25Cr2MoV”, and it is noted that “high-temperature tempering treatment, hardness HB220-250”;
• The dimension is marked with “valve body wall thickness ≥ 12mm, valve stem diameter ≥ 25mm”, and a “double valve stem nut” structure is adopted to improve strength;
• The sealing surface is marked with “nickel-based alloy surfacing, high-temperature hardness ≥ HRC35” to meet the high-temperature sealing requirements;
• The test is marked with “high-temperature seal test, temperature 180℃, pressure 4.4MPa, no leakage for 10 menit”.

For the gate valve drawings of farpro valve designed for high-temperature and high-pressure scenarios, the API 600 standard is cited, and it is marked that “the fire tempering test is qualified” to ensure safety under fire working conditions.

V. Common Misunderstandings and Practical Skills in Interpreting Gate Valve Drawings

In practical work, technical personnel often make misjudgments due to misunderstandings of drawing symbols and standard specifications, which affects valve selection and installation. The following summarizes common misunderstandings and shares practical interpretation skills.

5.1 Common Interpretation Misunderstandings

• Symbol Confusion: Confusing the symbols of “non-rising stem gate valve” Dan “rising stem gate valve”. The valve stem of the non-rising stem gate valve does not extend out of the handwheel in the drawing, while the valve stem of the rising stem gate valve moves up and down with opening and closing, and the symbol is marked with “Batang yang meningkat”.
• Parameter Neglect: Only focusing on DN and PN, while ignoring the working temperature. Misalnya, using ordinary carbon steel gate valves in working conditions above 200℃, resulting in high-temperature deformation of the valve body.
• Standard Conflict: Not paying attention to the standard version marked on the drawing. Misalnya, the structural length difference between GB/T 12234-2019 and the old version leads to mismatched installation dimensions.
• Material Misinterpretation: Confusing “CF8” (304 besi tahan karat) dengan “CF8M” (316 besi tahan karat), resulting in rapid damage to the valve in corrosive media.

5.2 Practical Interpretation Skills

• “First Check the Title, Then Refer to the Standards”: Obtain the valve model (MISALNYA., Z41W-16P) from the title block, where “Z” stands for gate valve, “4” for flange connection, “1” for wedge-type single gate, “W” for sealing surface material consistent with the valve body, “16” for PN16, Dan “P” for stainless steel. Then interpret the parameters by referring to the corresponding standards (MISALNYA., GB/T 12234).
• “Associate Dimensions with Working Conditions”: Combine structural dimensions with working conditions. Misalnya, for a DN100 PN40 gate valve, the valve body wall thickness is ≥6.4mm. If the drawing marks a wall thickness of 5mm, it is not suitable for high-pressure scenarios.
• “Check Technical Requirements One by One”: Focus on key requirements such as test pressure, leakage rate, and material standards, and compare them with actual needs. Misalnya, check the hygiene standards for drinking water scenarios.
• “Seek Technical Support from Enterprises”: For complex drawings, you can consult valve manufacturers. Misalnya, farpro valve provides professional drawing interpretation services and gives suggestions based on the actual performance of its products to avoid misjudgment.

VI. Kesimpulan: Gate Valve Drawings – The “Core Guide” for the Whole Life Cycle of Valves

The ability to interpret gate valve drawings is one of the core competencies of technical personnel in the valve industry. From parameter optimization in the design stage, to precision control in the production stage, to dimension matching in the installation stage and fault diagnosis in the maintenance stage, gate valve drawings run through the entire life cycle of the valve. Mastering the basic composition of the drawings, the marking of core components, technical standards, and scenario-based differences can not only improve work efficiency but also ensure the safe and stable operation of the pipeline system.

As an enterprise focusing on the R&D and production of stainless steel gate valves, farpro valve’s drawing design strictly complies with domestic and international standards, integrates years of industrial practical experience, and provides users with accurate and reliable technical documents. Whether you are a novice or a senior technical personnel, when interpreting gate valve drawings, you should maintain a rigorous and detail-oriented attitude with “standards as the guide”. When necessary, you can seek support from professional enterprises to make gate valve drawings truly become a “powerful weapon” for ensuring project quality.

Di masa depan, with the development of intelligent technology, gate valve drawings will gradually transform to “digitalization and 3Dization”, integrating BIM technology and Internet of Things parameters. The interpretation difficulty may be reduced, but the core requirements for professional knowledge will not change. Continuously learning drawing interpretation skills and paying attention to the update of industry standards is a necessary course for every valve practitioner.