Control Valve Locking Member for Unauthorized Adjustment Prevention
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Solution Overview
Problem
Conventional pressure independent control valves (PICVs) allow unauthorized adjustments to the manual adjuster, disrupting the desired flow rate and affecting heating or cooling performance, while qualified technicians need access for post-installation adjustments without removing the actuator.
Innovation Solution
A locking member for the control valve assembly that can be slid between unlocked and locked positions, restricting access to the manual adjuster when locked, and functioning as a tool for adjustments when unlocked, with features like tabs and recesses for engagement, allowing actuator installation without removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the manual adjuster is left accessible for post-installation adjustments, then qualified technicians can adjust the maximum flow rate without removing the actuator, but unqualified users may unauthorizedly adjust the manual adjuster disrupting the desired flow rate
Solution Approach 1:
The locking member is designed to be movable between a locked position (restricting access) and an unlocked position (allowing access). This dynamic element enables the system to switch between protection mode and adjustment mode, resolving the contradiction between security and accessibility.
Solution Approach 2:
The locking member acts as an intermediary between the manual adjuster and unqualified users. It provides a controlled interface that allows authorized adjustments while blocking unauthorized access, thus protecting the flow rate integrity while maintaining necessary accessibility.
2Reliability
If the locking member is designed to prevent removal when actuator is installed, then the manual adjuster remains protected, but the locking member must be complex to engage and disengage
Solution Approach 1:
The locking member combines multiple functions into a single component: it acts as both a protective cover and a adjustment tool. The tabs on the locking member engage with recesses on the manual adjuster, allowing the locking member to serve dual purposes of protection and adjustment, thereby reducing overall system complexity.
Solution Approach 2:
The locking member is designed with tabs that can engage with the manual adjuster's recesses, enabling it to function both as a security lock and as a adjustment tool. This multi-functionality eliminates the need for separate adjustment tools, reducing device complexity while maintaining security.
3Reliability
If the locking member completely blocks access to the manual adjuster, then unauthorized adjustments are prevented, but qualified technicians cannot make adjustments without removing the actuator
Solution Approach 1:
The locking member transitions between locked and unlocked states, dynamically controlling access to the manual adjuster. When unlocked, it allows qualified technicians to make adjustments; when locked, it prevents unauthorized changes. This dynamic behavior resolves the contradiction between stability and accessibility.
Solution Approach 2:
The locking member serves as a controlled intermediary that mediates access to the manual adjuster. It provides a regulated interface where authorized users can access the adjuster while unauthorized users are blocked, thus maintaining flow rate stability while enabling necessary adjustments.
Data Source
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AI summary
According to an aspect, there is provided a control valve assembly comprising: a control valve, the control valve comprising: a manual adjuster configured to allow a user to pre-set a flow value limit for the control valve; and an actuator adjuster configured to allow an actuator to interface with the control valve and adjust the flow value; wherein the control valve assembly further comprises: a locking member configured to selectively lock the manual adjuster and restrict user access to the manual adjuster when in a locked position.