Subsea Gate Valve Assembly With Recessed Impact-Protected Sealing

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Solution Overview

Problem

Gate valves in subsea workover systems face damage and sealing issues due to accidental drops of tool strings during emergency situations, leading to costly maintenance and potential system failure, as the tungsten carbide coating is brittle and prone to cracking under impact, affecting the sealing surface and requiring precise positioning for protection.

Innovation Solution

A gate valve design with recessed areas on the surface, removing the tungsten carbide coating within the valve bore diameter and slightly recessing the surface to protect the sealing area from mechanical damage, allowing the valve to tolerate dropped objects without compromising sealing performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the gate valve is equipped with tungsten carbide coating for wear resistance and sealability, then the gate can slide smoothly on the seat surface, but the coating is brittle and prone to cracking under impact from dropped objects

Engineering Contradiction:

Improvesmooth sliding of gateVSAvoidresistance to impact damage

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The gate surface is designed with different properties in different areas: the sealing area maintains the hard tungsten carbide coating for smooth sliding and sealing, while the impact-prone areas have a softer, more impact-resistant coating or material composition that can absorb dropped object impacts without cracking

Inventive Principle:

Principle #3Local quality

2Strength

If the gate valve sealing surface is made of hard material for wear resistance, then the gate can maintain sealing capability, but it cannot withstand concentrated load from dropped objects

Engineering Contradiction:

Improvewear resistance of sealing surfaceVSAvoiddamage from dropped objects

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

Different material properties are applied to different zones of the gate: the sealing surface retains hard tungsten carbide coating for wear resistance, while impact zones use softer, more ductile materials that can absorb impact energy without cracking

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The gate is pre-equipped with impact-absorbing features such as recessed areas or sacrificial zones that can absorb dropped object impacts before the force reaches the critical sealing surface, preventing crack propagation

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If the gate valve sealing surface is recessed to protect from dropped objects, then impact resistance is improved, but the positioning accuracy requirement increases

Engineering Contradiction:

Improveprotection from mechanical damageVSAvoidpositioning accuracy of gate

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The recess is designed to be localized to specific impact-prone areas rather than the entire sealing surface, maintaining precise positioning requirements only where needed for sealing while providing impact protection in other areas

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of recessing the entire sealing surface (which would compromise sealing), only portions of the gate surface are recessed to the extent necessary to absorb typical dropped object impacts, balancing protection with positioning tolerance

Inventive Principle:

Principle #16Partial or excessive action

4Productivity

If the gate valve is designed to tolerate dropped objects without damage, then maintenance needs are reduced, but the sealing surface must be protected from roughness that prevents smooth gate sliding

Engineering Contradiction:

Improvereduction of maintenance frequencyVSAvoidsmooth opening and closing of gate

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The gate surface is zoned with different properties: impact zones have rougher, more resilient surfaces that absorb dropped objects, while the sealing zones maintain smooth, hard coatings that enable frictionless sliding and reliable sealing

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The gate surface is segmented into distinct functional zones: impact-absorbing areas with sacrificial or resilient coating, and sealing areas with precision-hardened coating, allowing each zone to optimize its specific function without compromising the other

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11549331B2Gate valve assembly for a subsea workover system

Publication Date: 2023.01.10 ONESUBSEA AS

AI summary

The invention relates to a gate valve assembly (20) for use in a subsea workover system comprising: —a valve block (22) having a flow path (21c); —valve seats (33, 34) located within the valve block (22) around a periphery of the flow path (21c), —a gate valve member (40) which is moveable across the flow path (21c) between a first position in which the flow path (21c) is open and a second position in which the flow path (21c) is closed; —said gate valve member (40) comprising a first portion (31) surrounding an opening (32) adapted to mate with the flow path (21c) when the gate valve member (40) is in the first position, said first portion (31) is provided with a cutting member (30) arranged on the periphery of the first portion (31) towards the opening (32). The gate valve member (40) further comprises a second portion (41) having at least one recessed part (42, 43), said recessed part (42, 43) being positioned such that when the gate valve member (40) is in the second position, the gate valve member (40) and the seats (33, 34) forms a sealing area (44, 45) arranged on a planar surface of the gate valve member (40).