Product Overview
The THINKTANK TT-A42Y Series is a direct spring-loaded, full-lift enclosed high-pressure safety valve designed for overpressure protection of high-pressure equipment and piping systems.
The series includes TT-A42Y-160, TT-A42Y-320 and TT-A42Y-400 dimensional configurations. Depending on the selected version, sizes from DN15 to DN50 are listed in the dimensional data.
The TT-A42Y-160/320C configurations are intended for air, ammonia-hydrogen mixed gas and similar compatible media, while P/R configurations are available for corrosive gas service.
Flanged connections are designed in accordance with JB/T 2769.
Model Selection
TT-A42Y-160 / 320C
Suitable for equipment and piping systems handling:
- Air
- Ammonia-hydrogen mixed gas
- Similar compatible media
Maximum operating temperature: ≤200°C
TT-A42Y-160P/R & TT-A42Y-320P/R
Designed for equipment and piping systems handling:
- Corrosive gases
Maximum operating temperature: ≤200°C
Material compatibility should be verified according to the actual gas composition, concentration, operating pressure and temperature.
The dimensional table also lists a TT-A42Y-400 DN32 configuration. Since the provided product data does not specify its applicable medium or material configuration, these conditions should be confirmed separately for project selection.
Quick Specifications
| Parameter | Specification |
|---|---|
| Model Family | TT-A42Y |
| Listed Types | TT-A42Y-160 / TT-A42Y-320 / TT-A42Y-400 |
| Product Type | High-Pressure Spring-Loaded Safety Valve |
| Design | Direct Spring-Loaded |
| Lift Type | Full Lift |
| Construction | Enclosed Type |
| Connection | Flanged |
| Flange Standard | JB/T 2769 |
| Listed Size Range | DN15–DN50 depending on type |
| TT-A42Y-160/320C Media | Air, ammonia-hydrogen mixed gas and similar media |
| TT-A42Y-160/320C Temperature | ≤200°C |
| TT-A42Y-160P/R & 320P/R Service | Corrosive gases |
| P/R Maximum Temperature | ≤200°C |
| Manufacturer | THINKTANK |
How It Works
The TT-A42Y operates as a direct spring-loaded safety valve.
During normal operation, spring force keeps the valve disc seated and maintains the valve in the closed position.
When pressure in the protected equipment or pipeline reaches the specified set pressure, the pressure force acting on the disc overcomes the spring force and causes the valve to open.
The process gas is discharged through the valve outlet, reducing pressure in the protected system.
As system pressure falls into the reseating range, spring force moves the disc back toward the seat and the valve recloses automatically.
Full-Lift High-Pressure Design
The TT-A42Y combines a full-lift relieving design with construction intended for high-pressure service.
Under the general performance criteria applicable to this safety valve family:
Lift H ≥ 1/4 d₀
where:
- H = Valve lift
- d₀ = Orifice diameter
The full-lift design provides a larger available discharge area than a low-lift safety valve.
Because the TT-A42Y is intended for high-pressure applications, valve selection should not be based solely on nominal size. The selected configuration must be checked against the required set pressure, relieving pressure, capacity, temperature, back pressure and process medium.
Typical Applications
The TT-A42Y Series can be considered for:
- High-pressure compressed air systems
- Ammonia-hydrogen mixed-gas systems
- High-pressure gas process equipment
- Pressure vessels
- High-pressure process piping
- Packaged process equipment
- Skid-mounted high-pressure systems
- Corrosive gas service with the appropriate P/R configuration
Final selection should be based on the actual process composition, set pressure, operating and relieving temperature, required relieving capacity, back pressure and material compatibility.
General Performance Requirements
| Applicable Medium | Shell Test Pressure Ps | Seal Test Pressure Pm | Blowdown ΔP | Discharge Pressure Pp | Lift Height H |
| Steam | — | 90% Pk or the minimum reseating pressure, whichever is lower | When Pk ≤ 0.4 MPa: ΔP ≤ 0.04 MPa; when Pk > 0.4 MPa: ΔP ≤ 10% Pk | ≤ 1.03 Pk | Full-lift: ≥ 1/4 d₀; Low-lift: ≥ 1/20 d₀ |
| Air or other gases | 1.5 PN | When Pk ≤ 0.3 MPa: Pm = Pk − 0.03 MPa; when Pk > 0.3 MPa: Pm = 90% Pk | When Pk ≤ 0.2 MPa: ΔP ≤ 0.03 MPa; when Pk > 0.2 MPa: ΔP ≤ 15% Pk | ≤ 1.1 Pk | Full-lift: ≥ 1/4 d₀; Low-lift: ≥ 1/20 d₀ |
| Water or other liquids | — | When Pk ≤ 0.3 MPa: Pm = Pk − 0.06 MPa; when Pk > 0.3 MPa: Pm = 80% Pk | When Pk ≤ 0.3 MPa: ΔP ≤ 0.06 MPa; when Pk > 0.3 MPa: ΔP ≤ 20% Pk | ≤ 1.2 Pk | Full-lift: ≥ 1/4 d₀; Low-lift: ≥ 1/20 d₀ |
Notes:
- Pk = Set pressure
- d₀ = Orifice diameter
- PN = Nominal pressure
- Actual test and performance requirements shall be confirmed according to the selected valve model, project specification and applicable standard.
For the TT-A42Y Series, the full-lift criterion applies: H ≥ 1/4 d₀.
For the services specifically listed for this high-pressure series, the air or other gases performance requirements are the primary applicable row.
Dimensions – TT-A42Y-160
| Type | DN | d₀ (mm) | d (mm) | M | D (mm) | K (mm) | Z–φd | b (mm) | d₁ (mm) | C (mm) | M₁ | D₁ (mm) | K₁ (mm) | Z₁–φd | b₁ (mm) | L (mm) | L₁ (mm) | H Approx. (mm) |
| TT-A42Y-160 | 15 | 8 | 20 | M24×2 | 95 | 60 | 3-18 | 20 | 29 | 37 | M42×2 | 115 | 80 | 4-18 | 22 | 95 | 100 | 263 |
| TT-A42Y-160 | 20 | 10 | 27 | M33×2 | 105 | 68 | 3-18 | 20 | 29 | 37 | M42×2 | 115 | 80 | 4-18 | 22 | 95 | 100 | 263 |
| TT-A42Y-160 | 25 | 12 | 28 | M33×2 | 105 | 68 | 3-18 | 20 | 40 | 47 | M52×2 | 165 | 115 | 6-26 | 28 | 135 | 130 | 314 |
| TT-A42Y-160 | 32 | 15 | 37 | M42×2 | 115 | 80 | 4-18 | 22 | 50 | 59 | M64×3 | 165 | 115 | 6-26 | 32 | 150 | 150 | 390 |
| TT-A42Y-160 | 40 | 20 | 47 | M52×2 | 165 | 115 | 6-26 | 28 | 65 | 74 | M80×3 | 200 | 145 | 6-29 | 40 | 180 | 165 | 495 |
| TT-A42Y-160 | 50 | 25 | 59 | M64×3 | 165 | 115 | 6-26 | 32 | 80 | 94 | M100×3 | 225 | 170 | 6-33 | 45 | 190 | 190 | 510 |
Dimensions – TT-A42Y-320
| Type | DN | d₀ (mm) | d (mm) | M | D (mm) | K (mm) | Z–φd | b (mm) | d₁ (mm) | C (mm) | M₁ | D₁ (mm) | K₁ (mm) | Z₁–φd | b₁ (mm) | L (mm) | L₁ (mm) | H Approx. (mm) |
| TT-A42Y-320 | 15 | 8 | 27 | M33×2 | 105 | 68 | 3-18 | 20 | 29 | 37 | M42×2 | 115 | 80 | 4-18 | 22 | 95 | 100 | 263 |
| TT-A42Y-320 | 20 | 10 | 32 | M36×2 | 110 | 75 | 3-18 | 22 | 29 | 37 | M42×2 | 115 | 80 | 4-18 | 22 | 95 | 100 | 263 |
| TT-A42Y-320 | 25 | 12 | 35 | M42×2 | 115 | 80 | 4-18 | 22 | 40 | 47 | M52×2 | 165 | 115 | 6-26 | 28 | 135 | 130 | 314 |
| TT-A42Y-320 | 32 | 14 | 41 | M48×2 | 135 | 95 | 4-22 | 25 | 50 | 59 | M64×3 | 165 | 115 | 6-26 | 32 | 150 | 150 | 390 |
| TT-A42Y-320 | 40 | 18 | 58 | M64×3 | 165 | 115 | 6-26 | 32 | 65 | 74 | M80×3 | 200 | 145 | 6-29 | 40 | 180 | 165 | 495 |
| TT-A42Y-320 | 50 | 23 | 70 | M80×3 | 200 | 145 | 6-29 | 40 | 80 | 94 | M100×3 | 225 | 170 | 6-33 | 45 | 190 | 190 | 510 |
Dimensions – TT-A42Y-400
| Type | DN | d₀ (mm) | d (mm) | M | D (mm) | K (mm) | Z–φd | b (mm) | d₁ (mm) | C (mm) | M₁ | D₁ (mm) | K₁ (mm) | Z₁–φd | b₁ (mm) | L (mm) | L₁ (mm) | H Approx. (mm) |
| TT-A42Y-400 | 32 | 15 | 41 | M48×2 | 135 | 95 | 4-22 | 25 | 50 | 59 | M64×3 | 165 | 115 | 6-26 | 32 | 150 | 150 | 397 |
Dimensions are for preliminary engineering and layout reference. Final approved dimensional drawings should be confirmed before piping fabrication or installation.
Flange Standard
The flange dimensions for the TT-A42Y high-pressure safety valve series are designed in accordance with:
JB/T 2769
Project flange requirements should be checked against the actual piping specification before final valve selection.
Safety Valve Sizing and Selection
For correct selection of the TT-A42Y high-pressure safety valve, the following operating data should be established:
- Process medium and gas composition
- Set pressure
- Operating pressure
- Design pressure
- Operating temperature
- Relieving temperature
- Required relieving capacity
- Back pressure
- Required valve type
- Inlet and outlet connection dimensions
- Required materials
- Applicable project standards and certification requirements
- Installation and discharge arrangement
For ammonia-hydrogen mixed gas and other gas services, gas composition and relevant thermodynamic properties should be considered during relieving capacity evaluation.
Engineering Support
THINKTANK supports EPC contractors, system integrators, pressure equipment manufacturers, skid builders and industrial users with:
- High-pressure safety valve sizing and selection
- Relieving capacity calculation and review
- Set-pressure configuration
- Material compatibility review
- Dimensional drawings
- 3D models for system integration
- Existing safety valve replacement evaluation
- Project-specific technical documentation
THINKTANK has more than 30 years of industrial valve application experience and can support equivalent replacement and application review for high-pressure safety valve projects.
