Need More Details?
If you’d like to check stock availability, request the latest price, or view more product images, simply click the "Request for Price" button and our team will assist you promptly.

Carlyle 334‑108 Capacity Control Valve / Pressure Unloader Valve (Carrier 17‑55018‑01) – Efficient Refrigeration & HVAC Pressure Regulation Component
The Carlyle 334‑108 Capacity Control Valve, also referenced under Carrier part number 17‑55018‑01, is a high‑performance pressure unloader valve designed to manage and regulate refrigerant flow and discharge pressure in HVAC and refrigeration compressors. Engineered to deliver precise control over system capacity and pressure during varying load conditions, this valve plays a critical role in ensuring efficient, stable, and reliable operation of refrigeration systems, chillers, and HVAC units. With its robust design and precise regulation capabilities, the 334‑108 / 17‑55018‑01 valve supports improved energy efficiency, reduced system stress, and extended equipment lifespan.
Key Features
Accurate pressure relief and unloader function to safeguard compressor and HVAC systems from over‑pressure situations.
Efficient capacity control that helps stabilize system performance under variable load conditions, optimizing energy usage and operational stability.
Durable construction designed for continuous duty in refrigeration and HVAC environments, resisting wear and ensuring longevity.
Compatible with a variety of refrigerants and HVAC/R systems, facilitating integration into new or existing installations.
Enhances system reliability by reducing mechanical stress, preventing pressure surges, and ensuring consistent operation.
Specifications
Model: Carlyle 334‑108 Capacity Control / Pressure Unloader Valve (Carrier 17‑55018‑01)
Function: Pressure unloader / capacity control valve for refrigeration and HVAC compressors
Application: Suitable for refrigeration units, chillers, HVAC systems, and other applications requiring discharge pressure regulation and capacity modulation
Construction: Industrial / HVAC‑grade materials engineered for durability under continuous operation and exposure to refrigerants
Performance: Designed to maintain stable pressure control and efficient refrigerant flow under varying load and operating conditions
Manufacturer: Carlyle / Carrier
The Carlyle 334‑108 Capacity Control Valve (Carrier 17‑55018‑01) offers a dependable and efficient solution for pressure regulation and capacity modulation in HVAC and refrigeration systems. By ensuring precise control and protecting compressors from pressure-related stress, it supports improved system efficiency, safety, and service life. For procurement, technical support, or system integration assistance, Ram Automations is ready to help. Contact us at info@ramautomations.com to integrate this reliable pressure control valve into your HVAC or refrigeration applications.
Returns Policy
You may return most new, unopened items within 30 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Shipping
We can ship to virtually any address in the world. Note that there are restrictions on some products, and some products cannot be shipped to international destinations.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.