TT-A41Y Spring-Loaded Low-Lift Enclosed High-Pressure Safety Valve

Product Overview

The THINKTANK TT-A41Y Series is a direct spring-loaded, low-lift enclosed high-pressure safety valve designed for automatic overpressure protection of high-pressure equipment and piping systems.

The series includes TT-A41Y-160 and TT-A41Y-320 configurations, with nominal sizes from DN15 to DN50.

The TT-A41Y-160/320C configurations are suitable for air, ammonia-hydrogen mixed gas, water and similar compatible media. P/R configurations are available for corrosive gas or liquid service.

The listed maximum operating temperature is 200°C, and the flange dimensions are in accordance with JB/T 2769.

Model Selection

TT-A41Y-160 / TT-A41Y-320C

Suitable for equipment and piping systems handling:

• Air
• Ammonia-hydrogen mixed gas
• Water
• Similar compatible media

Maximum operating temperature: ≤200°C

TT-A41Y-160P/R / TT-A41Y-320P/R

Designed for equipment and piping systems handling:

• Corrosive gases
• Corrosive liquids

Maximum operating temperature: ≤200°C

Material compatibility should be verified according to the actual medium, gas composition or liquid concentration, pressure and temperature.

Quick Specifications

Parameter	Specification
Model Family	TT-A41Y
Listed Types	TT-A41Y-160 / TT-A41Y-320
Product Type	High-Pressure Spring-Loaded Safety Valve
Construction	Enclosed Type
Design	Direct Spring-Loaded
Lift Type	Low Lift
Connection	Flanged
Flange Standard	JB/T 2769
Size Range	DN15–DN50
TT-A41Y-160/320C Media	Air, ammonia-hydrogen mixed gas, water and similar media
TT-A41Y-160/320C Temperature	≤200°C
TT-A41Y-160P/R & 320P/R Service	Corrosive gases or liquids
P/R Maximum Temperature	≤200°C
Manufacturer	THINKTANK

How It Works

The TT-A41Y operates as a direct spring-loaded safety valve.

During normal operation, the spring applies force to the valve disc and keeps it seated against the valve seat.

When pressure in the protected equipment or piping system reaches the specified set pressure, the pressure force acting on the disc overcomes the spring force and causes the valve to begin opening.

The process medium is discharged through the outlet, reducing pressure within the protected system.

As system pressure decreases into the reseating range, spring force pushes the disc back toward the seat and the valve recloses automatically.

Low-Lift High-Pressure Design

The TT-A41Y combines a low-lift relieving configuration with construction intended for high-pressure service.

Under the general performance criteria applicable to this safety valve family:

Lift H ≥ 1/20 d₀

where:

• H = Valve lift
• d₀ = Orifice diameter

Compared with a full-lift safety valve, a low-lift design provides less valve travel relative to the orifice diameter. Valve selection must therefore be based on the required relieving capacity and process conditions rather than nominal connection size alone.

For applications requiring greater relieving capacity, the corresponding full-lift high-pressure TT-A42Y Series may be considered subject to engineering verification.

Typical Applications

The TT-A41Y Series can be considered for:

• High-pressure compressed air systems
• Ammonia-hydrogen mixed-gas systems
• High-pressure water systems
• High-pressure gas process equipment
• Pressure vessels
• High-pressure process piping
• Packaged process equipment
• Skid-mounted systems
• Corrosive gas or liquid service with the appropriate P/R configuration

Final selection should consider the actual process medium, set pressure, operating pressure, relieving temperature, required 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-A41Y Series, the low-lift criterion applies: H ≥ 1/20 d₀.

Because this series includes both gas and liquid applications, the applicable performance requirements should be selected according to the actual process medium.

Dimensions – TT-A41Y-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-A41Y-160	15	8	20	M24×2	95	60	3-18	20	29	37	M42×2	115	80	4-18	22	95	100	263
TT-A41Y-160	20	10	27	M33×2	105	68	3-18	20	29	37	M42×2	115	80	4-18	22	95	100	263
TT-A41Y-160	25	12	28	M33×2	105	68	3-18	20	40	47	M52×2	165	115	6-26	28	135	130	285
TT-A41Y-160	32	15	37	M42×2	115	80	4-18	22	50	59	M64×3	165	115	6-26	32	130	135	285
TT-A41Y-160	40	20	47	M52×2	165	115	6-26	28	65	74	M80×3	200	145	6-29	40	180	165	495
TT-A41Y-160	50	25	58	M64×3	165	115	6-26	32	80	94	M100×3	225	170	6-33	45	190	190	510

Dimensions – TT-A41Y-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-A41Y-320	15	8	27	M33×2	105	68	3-18	20	29	37	M42×2	115	80	4-18	22	95	100	263
TT-A41Y-320	20	10	32	M36×2	110	75	3-18	22	29	37	M42×2	115	80	4-18	22	95	100	263
TT-A41Y-320	25	12	35	M42×2	115	80	4-18	22	40	47	M52×2	165	115	6-26	28	135	130	285
TT-A41Y-320	32	14	41	M48×2	135	95	4-22	25	50	59	M64×3	165	115	6-26	32	130	135	285
TT-A41Y-320	40	18	58	M64×3	165	115	6-26	32	65	74	M80×3	200	145	6-29	40	180	165	495
TT-A41Y-320	50	23	70	M80×3	200	145	6-29	40	80	94	M100×3	225	170	6-33	45	190	190	510

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-A41Y high-pressure safety valve series are in accordance with:

JB/T 2769

The project piping specification and mating flange dimensions should be checked before final valve selection and manufacturing approval.

Safety Valve Sizing and Selection

For correct selection of the TT-A41Y high-pressure safety valve, provide:

• Process medium and 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 standards and certification requirements
• Installation and discharge arrangement

For ammonia-hydrogen mixed gas or other gas services, gas composition and relevant thermodynamic properties should be included in the relieving capacity evaluation.

For water and other liquid services, density and other relevant fluid properties may also be required.

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.