Stewarts-USA, LLC

6786 Tipperary Ln
Houston,  TX  77061

United States
  • Booth: 1061

We offer a comprehensive selection of high quality pressure & temperature gauges including sub-sea gauges, caisson & pneumo gauges, instrument valves & manifolds, and related accessories.

We are pleased to discuss the design & construction for special custom applications. ISO 9001:2015 certified manufacturer.

We welcome all inquiries.


  • Valves & Manifolds
    We offer a variety of precision engineered valves and 2, 3, and 5-valve manifolds in direct and remote mount styles with vent configurations to meet most flow, pressure and level measurement application requirements....

  • Stewarts works extensively with a large proportion of its clients in customising designs and configurations.  We are well equipped to reproduce any “special” valve manifold manufactured in the past.  We will also work with any client in tailoring and producing a
    precision product with any number of valves; configured to meet the specific requirements of the system.

    Also available from Stewarts is the G series range of valves for high pressure applications with design pressures currently to 20,000 and 30,000 psi.  Please see the G series catalogue for full details.

    Stewarts Valves & Manifolds have been designed to provide the safest possible connection and mounting of instruments.
    • 6000 psi standard Maximum Working Pressure
    • Hydrostatically tested to 1.5 times Maximum Working Pressure. In accordance with EN 12266
    • Full 316/316L St.St. Dual Certified, compliant to ISO 15156/NACE MR-01-75 & NORSOK M-630
    • Valves have trace code on body with original mill certificates available all to EN 10204-3.1
    • High Tolerance NPT Thread Engagement with 5-6 threads engaged when fully tightened
    • All valves and manifolds are individually boxed for protection and storage
    • Laser etching – valve detail on body
    • Bonnet locking pin safely locks the bonnet to body
    • Ø 4.76 Standard tip thru bore (CV = 0.4) Fully open

  • SUBSEA Compensated Stainless Steel Pressure Gauges
    The Stewarts-USA range of compensated subsea pressure gauges have a 100% filled case that has a special compensation device, allowing the
    internals of the case to be pressurized equal to the external ambient pressure as the gauge is submerged to depth....

  • The benefit of this method is that as the internal and external pressure remain in balance, there is no need for a pressure proof case, allowing our 8000 series subsea compensated gauges to work at your deepest depth applications. 
    Conventional (zero ref =1 atm) subsea pressure gauges rely on the strength of the case and window to withstand the external pressure of the water.
    A conventional (zero ref =1 atm) subsea gauge will compare the subsea reading to atmospheric or gauge pressure at the surface 
    (i.e. the zero point equals 1 atmosphere or approximately 1 bar absolute).  However, the compensated gauge will compare the subsea reading with the local ambient pressure at depth with the zero point being equal to the ambient pressure.  Provided the system being measured is also affected by this increase in ambient pressure, then the gauge reading will be correct.  However, if the system pressure is not affected by the increase in ambient pressure, the gauge will start to read increasingly low as the depth increases.
    Unique features
    • We offer two types of compensation.  Our unique welded stainless steel diaphragm (for durability) (8022/8024)  & the conventional Nitrile rubber diaphragm (8032/8034).
    • Robust 316 Stainless Steel  Case/ Bezel / Socket & Element, removable bezel design allows repair or recalibration.
    • Stewarts-USA has also developed a exclusive Aegis-Guard (Acrylic) which will offer protection to the gauge in the event of external contact. This will aid in protection against subsea construction and remediation applications when using subsea tooling or ROV’s .  The cover can be replaced manually if damaged, mitigating the need to replace an entire gauge.
  • Heavy Duty, All Stainless Steel Gauges
    Dry, Liquid Fillable or Pre-Filled. VIBRAGAUGE® Option also available. VIBRAGAUGE® for Dampening of vibration & pulsation without liquid filling....

  • - Case pressure-relief grommet 
    - White-painted aluminium dial, Black-printed figures.
    - Black-anodised aluminium pointer (Micrometer adjustable on 4” & 6”).
    - AISI 316 Stainless Socket & Element.
    - AISI 316 Stainless Steel Case & Bayonet Ring (standard).
    - IP66. Oper temp range: -4°F to 140°F (-20° to 60°C) w/o loss of accuracy.
    - Orifice Restrictor Screw (standard Ø0.9mm, Ø0.4mm on request).
    - LENS: Laminated Safety Glass 4mm (0.16” thick)
    - ACCURACY* (*UnDampened, Dry): 
    0-10,000 psi = 0.5% of span on 4” & 6” (1.0% on 2½” & 4" & 6" with Vibragauge).
    0-15,000 psi = 1.0% of span on 4” & 6” (1.5% on 2½”)   
    0-20 KSI+    = 1.5% of span (1.5% of span (Also inches on Inches of H2O ranges).