Delta T, a brand of Max-Air Technology, is dedicated to the manufacturing and distribution of high-quality valve products to the flow control industry. Delta T is focused on quarter turn butterfly valve solutions, from standard resilient butterfly valves, high performance valves (double and triple offset), control butterfly valves, as well as manual gearing, declutchable gearing, stem extensions, and chain & handwheel options. We also are well versed in tee and wye assemblies with linkage.

800 Series

High Performance
Double Offset

C Series

Cavitation Control
Double Offset

900 Series

Triple Offset

Need information on how to get our products? Send us an inquiry!


800 Series | Double Offset

High Performance

(Series 850, 851, 852, 853, 860, 861, 862, 863, 871)

  • ANSI 150, 300, & 600 in all styles
  • Wafer, Lugged, & Flanged styles
  • WCB & CF8M bodies stocked
    (A broad selection of other materials available)
  • Blow out proof stem design
  • Stainless Steel disc & stem standard on stocked trims
  • TFM 1600 seats are standard, other soft seats are available
  • Fire Safe & Metal seated versions are available
  • ISO 5211 mounting is standard. (Direct mount for 12” & smaller, w/ included bracket on larger size)
  • Class VI / bubble tight bi-directional sealing on all soft seated trims
  • Dead End service to full pressure rating in preferred direction
  • Control trim w/ anti-noise & anti-cavitation features available

Sales Literature

Submittal Drawings

IOM Manual

Series Designations

  • 850 – CLASS 150 – ANSI/DIN WAFER
  • 851 – CLASS 150 – ANSI LUG
  • 852 – CLASS 150 – DIN LUG
  • 853 – CLASS 150 – ISO 5752 FLANGED (SHORT)
  • 860 – CLASS 300 – ANSI/DIN WAFER
  • 861 – CLASS 300 – ANSI LUG
  • 862 – CLASS 300 – DIN LUG
  • 863 – CLASS 300 – ISO 5752 FLANGED (SHORT)
  • 871 – CLASS 600 – ANSI LUG

C Series | Double Offset

High Performance

Cavitation Control

(Series C50, C51, C52, C53, C60, C61, C62, C63)

Diffuser is defined as “A device for reducing the velocity and increasing the static pressure of a fluid passing through a system”. Delta T’s unique diffuser plate butterfly valve does that by incorporating a spherical edged disc with the diffuser plate to direct and diffuse the flowstream. This optimizes the ability to control flow and minimizes noise, cavitation and damaging high velocity jets of fluid. In the first 30° of rotation, when pressure drop is the highest, the spherical edged disc constrains the flow, directing it through the diffuser to minimize the potential for damaging flow conditions.

  • ANSI Class 150 and 300 in Wafer, Lugged, & Flanged body styles
  • Available in a broad selection of materials
  • WCB and CF8M bodies standard
  • CF8M Stainless Steel disc and stem standard
  • Soft, fire safe, & metal seats available
  • Metal seats (high temperature, corrosive services, metallurgical-sensitive applications) w/ Class IV shutoff
  • ISO 5211 actuator mounting is standard, direct mounting on 12 inch and smaller
  • Control & anti-cavitation trim plate provides a high level of control and noise reduction within the first 30° of rotation
  • Soft seated trims offer bi-directional class VI shutoff
  • Clean, field repairable design

Patented Spherical-Disc Diffuser-Plate Design

This is NOT just a modified butterfly valve; it is uniquely patented design that overcomes some of the limitations of classic control valves. Compared to the industry standard Globe Valve, this design has improved control at lower flow rates, better range-ability, higher flow capacity, reduced noise and vibration, and all at a lower cost.

Sales Literature

Submittal Drawings

IOM Manual

Design Advantages 

  • Unparalleled Range-Ability w/ Equal Percentage Flow
    Controllable Range 5°-85° (Rangeability up to ~600:1)
    Optimal Control Range 10°-70° (Rangeability up to ~100:1) 
  • Fine-Tuned Low Flow Control and High Flow Capacity 
  • Reduced Noise & Vibration 

Series Designations

  • C50 – CLASS 150 – ANSI/DIN WAFER
  • C51 – CLASS 150 – ANSI LUG
  • C52 – CLASS 150 – DIN LUG
  • C53 – CLASS 150 – ISO 5752 FLANGED (SHORT)
  • C60 – CLASS 300 – ANSI/DIN WAFER
  • C61 – CLASS 300 – ANSI LUG
  • C62 – CLASS 300 – DIN LUG
  • C63 – CLASS 300 – ISO 5752 FLANGED (SHORT)

900 Series | Triple Offset

(Series 950, 951, 952, 953, 954, 960, 961, 962, 963, 964, 970, 971, 972, 973, 974)

  • ANSI 150, 300, & 600 in all styles
  • Wafer, Lugged, & Flanged styles
  • A broad selection of materials available
  • Blow Out Proof stem design
  • Stainless Steel disc & stem standard on stocked trims
  • TFM 1600 Seats are standard, other soft seats are available
  • Fire Safe & Metal seated versions are available
  • Class VI / Bubble Tight sealing in preferred direction
  • Dead End Service to full pressure rating in preferred direction
  • Replaceable body disc

Sales Literature

Submittal Drawings

Series Designations

  • 950 – CLASS 150 – ANSI/DIN WAFER
  • 951 – CLASS 151 – ANSI LUG
  • 952 – CLASS 152 – DIN LUG
  • 953 – CLASS 153 – ISO 5752 FLANGED (SHORT)
  • 954 – CLASS 154 – B16.10 FLANGED (LONG)
  • 960 – CLASS 300 – ANSI/DIN WAFER
  • 961 – CLASS 301 – ANSI LUG
  • 962 – CLASS 302 – DIN LUG
  • 963 – CLASS 303 – ISO 5752 FLANGED (SHORT)
  • 964 – CLASS 304 – B16.10 FLANGED (LONG)
  • 970 – CLASS 600 – ANSI/DIN WAFER
  • 971 – CLASS 601 – ANSI LUG
  • 972 – CLASS 602 – DIN LUG
  • 973 – CLASS 603 – ISO 5752 FLANGED (SHORT)
  • 974 – CLASS 604 – B16.10 FLANGED (LONG)