Maxitrol manufactures gas pressure regulators for residential, commercial, and industrial applications. These regulators are designed for use with natural gas, propane, and other gas mixtures. Several models incorporate or can be fitted with vent limiting devices and other accessories to enhance functionality and safety. Proper installation and orientation are critical for optimal performance, particularly when utilizing vent limiting features. This article details the installation considerations, available accessories, and model-specific guidance based on official Maxitrol documentation.
Understanding Vent Limiting Devices
Maxitrol vent limiting devices are designed to restrict gas escapement in the event of diaphragm failure, making them suitable for indoor use and spaces where minimizing gas release is paramount. These devices are not intended for outdoor applications where exposure to the elements could compromise their function. The documentation emphasizes that Maxitrol vent limiting devices should only be installed in regulators with which they are certified.
The use of a vent limiting device often necessitates specific mounting orientations. Regulators equipped with these devices, such as the 325-3 and 325-5A models, must be mounted in an upright horizontal position. Any other orientation can cause the internal ball check to close, restricting gas flow, increasing lock-up pressure, slowing response time, and preventing the regulator from operating as designed.
Several vent limiting devices are available, each designed for specific regulator models and vent port sizes. These include: 12A04, 12A09, 12A39, and 12A49. The documentation specifies maximum inlet pressure ratings when using certain vent limiters, such as 2 psi (140 mbar) for LP gas and 5 psi (345 mbar) for natural gas when using 12A09 or 12A39 devices.
Accessory Options for Maxitrol Regulators
Beyond vent limiting devices, Maxitrol offers a range of accessories to address various installation and environmental concerns. These include:
- Vent Protectors: Designed for outdoor applications, vent protectors (models 13A15, 13A15-5, and 13A25) shield the vent opening from rain, snow, dust, insects, and other foreign particles. These protectors must be mounted in an upright position. Specific models are compatible with different vent port sizes: 13A15 for 1/8” NPT, 13A15-5 for 3/8” NPT, and 13A25 for 1/2” NPT. They are intended for use with the 325-3, 325-3L, RV48, RV52, RV53, RV61, R500(S)(Z), and R600(S)(Z) models.
- Vent Dampeners: Models KVOP-3 and KVOP-4 are designed for use with specific regulator models (KVOP-3 for 325-5 and 325-5L; KVOP-4 for 325-7A, 325-7AL, and 325-9L). Importantly, vent dampeners should not be used in conjunction with vent limiters.
- Vent Screens: Brass, 40-mesh screens (models 13A03-1 through 13A03-6) act as flame arrestors, preventing ignition of gas-air mixtures within the diaphragm chamber. These screens are available for vent sizes ranging from 1/8” to 3/4” NPT.
- Pressure Tap Connectors: The PF10 connector provides a convenient hose fitting for testing inlet and outlet pressures, eliminating the need for specialized barb fittings.
- Dust Caps: These caps prevent blockage of the breather hole from dust and debris.
Model-Specific Installation Notes
The documentation provides specific installation guidance for several Maxitrol regulator series:
- 325-L Series: These regulators are designed for 2 psi piping systems and are suitable for multi-positional mounting unless a ball check vent limiting device is installed, in which case upright mounting is mandatory. The 325-3L, 325-5L, 325-7AL, and 325-9L models feature aluminum housings.
- 325 Series: Similar to the 325-L series, these regulators support multi-positional mounting unless a vent limiting device is used. The 325-3, 325-5, 325-7A, 325-9, and 325-11 models also have aluminum housings.
- RV Series: Most RV series models are suitable for multi-positional mounting, with the exception of “D” suffix models, which must be mounted upright. If a ball check vent limiting device is installed, upright mounting is required. The RV series is certified to ANSI Z21.18/CSA 6.3 standards.
- RV47: Pipe sizes range from 1/8” to 3/4” with threaded connections.
- 325-3, 325-3L: These models require a 1/8” NPT vent tap and are compatible with the 12A09 vent limiting device or 13A15 vent protector.
- 325-5, 325-5L: These models utilize a 3/8” NPT vent tap and are compatible with the 12A39 vent limiting device or 13A15-5 vent protector.
- 325-7A, 325-7AL: These models feature a 1/2” NPT vent tap and are compatible with the 12A49 vent limiting device or 13A25 vent protector.
- 325-9, 325-9L: These models also utilize a 1/2” NPT vent tap and are compatible with the 12A49 vent limiting device or 13A25 vent protector.
- R400(S), R500(S), R600(S): These models have a 1/8” NPT vent tap and are compatible with the 12A04 vent limiting device.
- OPD47, OPD48, OPD600: These models have an integral vent limiting orifice and include a dust cap.
- OPD210D, OPD210E: These models have a 1/8” NPT vent tap and are compatible with the 12A09 vent limiting device or 13A15 vent protector.
Capacity and Specifications
The 325 series regulators offer varying capacities based on model and pipe size. The 325-3 has a capacity of 150,000 Btu/hr with 3/8” or 1/2” pipe sizes. The 325-5A can handle 300,000 Btu/hr with 1/2”, 3/4”, or 1” pipe sizes. The 325-7 can manage 1,000,000 Btu/hr with 1-1/4” or 1-1/2” pipe sizes. Maximum individual load ratings are also model-specific: 100,000 Btu/hr for the 325-3, 250,000 Btu/hr for the 325-5A, and 900,000 Btu/hr for the 325-7.
The documentation notes that all Maxitrol gas pressure regulators should be installed and operated in accordance with the Maxitrol Safety Warning Instructions (GPRCSA2PSIMIEN.FR or GPRMIEN.ES).
Conclusion
Proper installation and accessory selection are crucial for the safe and efficient operation of Maxitrol gas pressure regulators. Understanding the specific requirements of each model, particularly regarding mounting orientation when using vent limiting devices, is essential. The documentation clearly outlines the compatibility of various accessories and provides model-specific guidance to ensure optimal performance. Always refer to the official Maxitrol Safety Warning Instructions for complete installation and operational procedures.